diff --git a/site/src/modules/workspaces/DynamicParameter/DynamicParameter.tsx b/site/src/modules/workspaces/DynamicParameter/DynamicParameter.tsx
index 72113ce8f504b..35c5763c23d25 100644
--- a/site/src/modules/workspaces/DynamicParameter/DynamicParameter.tsx
+++ b/site/src/modules/workspaces/DynamicParameter/DynamicParameter.tsx
@@ -84,6 +84,7 @@ export const DynamicParameter: FC<DynamicParameterProps> = ({
 						value={value}
 						onChange={onChange}
 						disabled={disabled}
+						isPreset={isPreset}
 					/>
 				) : (
 					<ParameterField
@@ -231,6 +232,7 @@ interface DebouncedParameterFieldProps {
 	onChange: (value: string) => void;
 	disabled?: boolean;
 	id: string;
+	isPreset?: boolean;
 }
 
 const DebouncedParameterField: FC<DebouncedParameterFieldProps> = ({
@@ -239,6 +241,7 @@ const DebouncedParameterField: FC<DebouncedParameterFieldProps> = ({
 	onChange,
 	disabled,
 	id,
+	isPreset,
 }) => {
 	const [localValue, setLocalValue] = useState(
 		value !== undefined ? value : validValue(parameter.value),
@@ -251,19 +254,26 @@ const DebouncedParameterField: FC<DebouncedParameterFieldProps> = ({
 
 	// This is necessary in the case of fields being set by preset parameters
 	useEffect(() => {
-		if (value !== undefined && value !== prevValueRef.current) {
+		if (isPreset && value !== undefined && value !== prevValueRef.current) {
 			setLocalValue(value);
 			prevValueRef.current = value;
 		}
-	}, [value]);
+	}, [value, isPreset]);
 
 	useEffect(() => {
-		if (prevDebouncedValueRef.current !== undefined) {
+		// Only call onChangeEvent if debouncedLocalValue is different from the previously committed value
+		// and it's not the initial undefined state.
+		if (
+			prevDebouncedValueRef.current !== undefined &&
+			prevDebouncedValueRef.current !== debouncedLocalValue
+		) {
 			onChangeEvent(debouncedLocalValue);
 		}
 
+		// Update the ref to the current debounced value for the next comparison
 		prevDebouncedValueRef.current = debouncedLocalValue;
 	}, [debouncedLocalValue, onChangeEvent]);
+
 	const textareaRef = useRef<HTMLTextAreaElement>(null);
 
 	const resizeTextarea = useEffectEvent(() => {
@@ -513,7 +523,9 @@ const ParameterField: FC<ParameterFieldProps> = ({
 						max={parameter.validations[0]?.validation_max ?? 100}
 						disabled={disabled}
 					/>
-					<span className="w-4 font-medium">{parameter.value.value}</span>
+					<span className="w-4 font-medium">
+						{Number.isFinite(Number(value)) ? value : "0"}
+					</span>
 				</div>
 			);
 		case "error":
diff --git a/site/src/pages/WorkspaceSettingsPage/WorkspaceParametersPage/WorkspaceParametersPageExperimental.tsx b/site/src/pages/WorkspaceSettingsPage/WorkspaceParametersPage/WorkspaceParametersPageExperimental.tsx
index 781f8b12e8c67..e80542f3144da 100644
--- a/site/src/pages/WorkspaceSettingsPage/WorkspaceParametersPage/WorkspaceParametersPageExperimental.tsx
+++ b/site/src/pages/WorkspaceSettingsPage/WorkspaceParametersPage/WorkspaceParametersPageExperimental.tsx
@@ -26,6 +26,7 @@ import { useMutation, useQuery } from "react-query";
 import { useNavigate } from "react-router-dom";
 import { docs } from "utils/docs";
 import { pageTitle } from "utils/page";
+import type { AutofillBuildParameter } from "utils/richParameters";
 import {
 	type WorkspacePermissions,
 	workspaceChecks,
@@ -39,11 +40,27 @@ const WorkspaceParametersPageExperimental: FC = () => {
 	const navigate = useNavigate();
 	const experimentalFormContext = useContext(ExperimentalFormContext);
 
+	// autofill the form with the workspace build parameters from the latest build
+	const {
+		data: latestBuildParameters,
+		isLoading: latestBuildParametersLoading,
+	} = useQuery({
+		queryKey: ["workspaceBuilds", workspace.latest_build.id, "parameters"],
+		queryFn: () => API.getWorkspaceBuildParameters(workspace.latest_build.id),
+	});
+
 	const [latestResponse, setLatestResponse] =
 		useState<DynamicParametersResponse | null>(null);
 	const wsResponseId = useRef<number>(-1);
 	const ws = useRef<WebSocket | null>(null);
 	const [wsError, setWsError] = useState<Error | null>(null);
+	const initialParamsSentRef = useRef(false);
+
+	const autofillParameters: AutofillBuildParameter[] =
+		latestBuildParameters?.map((p) => ({
+			...p,
+			source: "active_build",
+		})) ?? [];
 
 	const sendMessage = useEffectEvent((formValues: Record<string, string>) => {
 		const request: DynamicParametersRequest = {
@@ -57,11 +74,34 @@ const WorkspaceParametersPageExperimental: FC = () => {
 		}
 	});
 
+	// On page load, sends initial workspace build parameters to the websocket.
+	// This ensures the backend has the form's complete initial state,
+	// vital for rendering dynamic UI elements dependent on initial parameter values.
+	const sendInitialParameters = useEffectEvent(() => {
+		if (initialParamsSentRef.current) return;
+		if (autofillParameters.length === 0) return;
+
+		const initialParamsToSend: Record<string, string> = {};
+		for (const param of autofillParameters) {
+			if (param.name && param.value) {
+				initialParamsToSend[param.name] = param.value;
+			}
+		}
+		if (Object.keys(initialParamsToSend).length === 0) return;
+
+		sendMessage(initialParamsToSend);
+		initialParamsSentRef.current = true;
+	});
+
 	const onMessage = useEffectEvent((response: DynamicParametersResponse) => {
 		if (latestResponse && latestResponse?.id >= response.id) {
 			return;
 		}
 
+		if (!initialParamsSentRef.current && response.parameters?.length > 0) {
+			sendInitialParameters();
+		}
+
 		setLatestResponse(response);
 	});
 
@@ -149,6 +189,7 @@ const WorkspaceParametersPageExperimental: FC = () => {
 	const error = wsError || updateParameters.error;
 
 	if (
+		latestBuildParametersLoading ||
 		!latestResponse ||
 		(ws.current && ws.current.readyState === WebSocket.CONNECTING)
 	) {
@@ -202,6 +243,7 @@ const WorkspaceParametersPageExperimental: FC = () => {
 			{sortedParams.length > 0 ? (
 				<WorkspaceParametersPageViewExperimental
 					workspace={workspace}
+					autofillParameters={autofillParameters}
 					canChangeVersions={canChangeVersions}
 					parameters={sortedParams}
 					diagnostics={latestResponse.diagnostics}
diff --git a/site/src/pages/WorkspaceSettingsPage/WorkspaceParametersPage/WorkspaceParametersPageViewExperimental.tsx b/site/src/pages/WorkspaceSettingsPage/WorkspaceParametersPage/WorkspaceParametersPageViewExperimental.tsx
index a8679a82b8316..4fe9d19c956d1 100644
--- a/site/src/pages/WorkspaceSettingsPage/WorkspaceParametersPage/WorkspaceParametersPageViewExperimental.tsx
+++ b/site/src/pages/WorkspaceSettingsPage/WorkspaceParametersPage/WorkspaceParametersPageViewExperimental.tsx
@@ -16,9 +16,11 @@ import {
 } from "modules/workspaces/DynamicParameter/DynamicParameter";
 import type { FC } from "react";
 import { docs } from "utils/docs";
+import type { AutofillBuildParameter } from "utils/richParameters";
 
 type WorkspaceParametersPageViewExperimentalProps = {
 	workspace: Workspace;
+	autofillParameters: AutofillBuildParameter[];
 	parameters: PreviewParameter[];
 	diagnostics: PreviewParameter["diagnostics"];
 	canChangeVersions: boolean;
@@ -34,6 +36,7 @@ export const WorkspaceParametersPageViewExperimental: FC<
 	WorkspaceParametersPageViewExperimentalProps
 > = ({
 	workspace,
+	autofillParameters,
 	parameters,
 	diagnostics,
 	canChangeVersions,
@@ -42,17 +45,32 @@ export const WorkspaceParametersPageViewExperimental: FC<
 	sendMessage,
 	onCancel,
 }) => {
+	const autofillByName = Object.fromEntries(
+		autofillParameters.map((param) => [param.name, param]),
+	);
+	const initialTouched = parameters.reduce(
+		(touched, parameter) => {
+			if (autofillByName[parameter.name] !== undefined) {
+				touched[parameter.name] = true;
+			}
+			return touched;
+		},
+		{} as Record<string, boolean>,
+	);
 	const form = useFormik({
 		onSubmit,
 		initialValues: {
-			rich_parameter_values: getInitialParameterValues(parameters),
+			rich_parameter_values: getInitialParameterValues(
+				parameters,
+				autofillParameters,
+			),
 		},
+		initialTouched,
 		validationSchema: useValidationSchemaForDynamicParameters(parameters),
 		enableReinitialize: false,
 		validateOnChange: true,
 		validateOnBlur: true,
 	});
-
 	// Group parameters by ephemeral status
 	const ephemeralParameters = parameters.filter((p) => p.ephemeral);
 	const standardParameters = parameters.filter((p) => !p.ephemeral);