entering an "=" unexpectedly breaks "in" at a distance

[disconcision]

given:

entering "=" (was trying to insert arrow type before remembering we dont have them) yields:

breaking the in

[dm0n3y]

hmm interesting... I've been allowing breaking the edit site's parent bidelimited container bc that's needed for eg turning [a,b,c,d] into [a,b]@[c,d] just by typing over middle comma. but maybe should just be a brace-specific thing