This will also helps in reducing the output.xml file size for cases where keywords are using loops. Currently they generate all log messages in output.xml. These type of keywords can be set to log level NONE so that they do not generate large number of log messages while looping through and if required for debug etc. log level can be set accordingly to generate them if required.

Do you mean that if you use --loglevel NONE and then have, for example, Log    Message in your test, the logged message is visible? That would be strange because we have tests for this functionality and I also believe someone else would have reported the problem if our tests had detected it.

Alternatively, do you mean that if you have that Log    Message in a test, arguments are shown in the log file regardless the log level? In this case when the message is plain text, it means that the actual message is shown. If the message would be a variable like Log    ${message}, you only see the variable in arguments and the actual value is shown as the logged message (that ought to honor the log level).

I think the issue is when I use robot:flatten tag on the keyword it logs at INFO level even if I have set the log level to NONE, I can see log messages in output.xml and also in normal log.html file

Here is the sample test.robo which should reproduce the issue

*** Settings ***

*** Variables ***
${user}    dummyuser
${secret}    ThisIsSecret!

*** Keywords ***
Create App Session
    Create Web Session

Create Web Session
    [Documentation]    Does something related to creating a web session
    
    [Tags]    robot:flatten
    ${log}    Set Log Level    NONE
    ${auth}    Create List    ${user}    ${secret}
    Log To Console    Calling a keyword which create web sesson with application     
    Set Log Level    ${log}


*** Test Cases ***
Test Logging     
    Create App Session
    Log To Console    Using session to do some more testing

Have you verified this issue occurs also with RF 7.0? See #4921.

I have not tried on RF 7.0 as we using 6.1.1 only currently. Are there any plans to back port fix? What is the LTS version for RF?

We don't have resources to backport fixes or to have LTS versions. I hope you can test with RF 7.0 so that we know is the issue resolved or not.

I expect this to be a duplicate of #4921.