if you want to have a serious discussion about donnie's gifts and what it implies i think the soft shell thing was brought up so heavily because the gifts in general were projection (i actually just saw a post that mentioned the final shot including him facing away from the camera, putting the focus specifically on his battle shell while he tells them they're perfect the way they are, which is very good visual storytelling to display that. maybe he understands that about them now, but he does he understand that about himself?). it was never given the chance to be explored in-depth but i think its quite obvious that his battle shell is a physical metaphor of the way that he covers up his inadequacies with his tech, and how he feels like the fixer, the science guy, who centers his self-worth around his use. in the deleted version of the confrontation scene in donnie vs witch town, it's even implied that he was afraid of being abandoned if they didn't need him anymore. he's a deeply insecure person and that does influence the way he treats others.
meanwhile i think people overstate how horrible the shock collar is ... compared it in the notes of that post but they bickered over it like moving things around on the chore chart. it was clear that the gifts in particular were hurtful, but they were over it the moment that they got to pettily get back at him, and he did so quickly concede once he understood why they didnt like it. they were pretty quick to deny the idea that they actually needed to be corrected. they just found it annoying and frustrating, and raph baby-talking and being scared to confront him was specifically a him-thing, yeah. i do think raph feels a degree of responsibility over the two youngest and that's why he treats them like that, but it doesnt stop them from getting fed up with them-- he is all the time! with donnie's gifts in particular it's kind of because he OPENED with a guilt-trip and also like,,, it's his tech. this is something extremely important to him. disapproval for the thing that he has centered his whole life around is going to hurt, and that's made apparent in several episodes-- there's nothing he hates more than being unappreciated or taken advantage of. of being easy to discard. his work is an extension of himself.
and even then, raph got over it when he hit a certain point lmao. and it's important to note that mikey and leo share none of those reservations! if they're not mad at him when he does something shitty, it's because they dont find it hurtful. they're not going to spare his feelings-- they go out of their way to get back at him when he hurts theirs.
