Aaah I actually used to be selective mute as a kid (and let me tell you it sucks a lot and is kind of scary) so I like that you see Ludger that way
Bruh when I was in high school mutism was my main defense mechanism and it SUCKED like oh you really want to know why I’m not talking today well....I can’t tell you....so bye....yeah sorry wait until tomorrow and maybe I won’t shut down when you ask me what the fuck happened
Of course I don’t see Ludger being selectively mute out of any negative conditions, I’m sure it’s just how he is, but of course it probably causes him a lot of problems as well. Like, I’m 100% certain Julius was the one who got him that job at the cafeteria by pulling some strings for him and possibly even doing the interview alongside him. And the way he does things over the GHS, like I’m sure if it weren’t his old college buddy Nova trying to wring him for cash he’d probably have to pass his GHS to someone else. Vera probably doesn’t care how responsive Ludger is but eventually got the run-down from her sister at some point.
And the APD thing comes from basically the way the choice game mechanic works, like I can just picture Luds taking a second or two to take in what’s being said and form a response, like the way there’s a shortened version of what was just said at the bottom of the screen really reminds me of how I basically have to re-arrange sentences that were never out of order in the first place in my head before I really understand what’s being said.
My SPD Julius headcanon comes from, mostly, his obsession with tomato dishes and his inability to cook for himself, like that really speaks to me in the sense that like, he probably fixates on his favourite food as a base ingredient because he has trouble finding other flavours and textures that he likes, and it’s hard to cook for someone else when you can’t even bear to taste or smell half the ingredients you’re using (lmao I SHOULD KNOW). Plus the humming seems to me like a perfect calming stim for him, and he’s got that big ol’ ring on his right hand that could be useful for twiddling around with too.