Honestly i didn't think of Thantos like that either but i think thats because his size makes me think micro/macro kink which i don't have, i find the logistics of it hard to wrap my head around.
I think our scope was limited in just considering the rat body when Thanatos is more than that.
Because yeah, if someone truly has ThanatosxDave as their favorite they could write Thanatos into any robotic form they wanted. I've jokingly thought about putting him into an Alexa type thing or going full Shodan. But I guess he could be put into whatever if it's the realm of fanfiction?
I suppose, its just Thanatos isn't an AI and doesn't have free will so anything he does needs to be within the confines of the experiment. Can't really have a glados experiance since he isn't and AI. I think there might also be limits on what he's able to do since it would be easier to make more droids? minions? im sure you know what im getting at but yes it would be easier rather than using Dave's friends to just use created minions to move all the pieces and do the killing he needs but he never does. Either there isn't enough resources or he has limits placed on him to stop it, he doesn't even have a back up body which considering how many times Dave tries to break him is just odd.
And now i realise my flaw, if they really want a porn fanfic they don't care about logic. I really should just stop thinking sometimes.