Is this still a thing?
Easy fix: you can't open cupboard if it's hitbox overlaps with another hitbox, but it can be lifted. This way stacked CBs can't be used as quantum storage but accidentally/properly (when abandoned building has decayed) stacked cupboards can be salvaged.
SnuggleSnail has insisted that newbs actually benefit more from CB stacking than bots and some arguments actually make sense, such as time is a non-issue for a bot and once you do build the storage infrastructure, it's free to use forever.
Following questions however, were left unanswered:
A) How cupboards are actually stacked? (Can't use technique you donät know how to pull off.)
B) Not explaining how you're supposed to find anything from stack of cupboards without a bot. (Manually, you'd have to somehow click different CBs that overlap with each other and then find the right one.)