What more do beta testers need to do to get the message across, seriously????
Well, if we're venting spleens, let me do as well. 
IMO, some of beta testers have been their own worst enemies on this subject because they keep confusing two SEPARATE complaints into one. Namely, building multiple things at once and having excess production spill over to the next project. They aren't at all the same thing.
Yet each and EVERY TIME the subject of production comes up, the Bulid Multiple Things At Once folks immediately muddy the waters when production concerns are raised.
No wonder Paul is close to tearing his hair out on the subject. Each and every time he tries to explain what is intended a crowd shouts him down and starts talking about Build Multiple Things.
Well, it's clear that is not happening. So for those of us who want to see things as intended, please for the love of whatever deity or concept you like STOP BRINGING MULTIPLE THINGS AT ONCE UP!
Really, I'm begging now. Just. Stop. 
The thing is, Paul seems to think overflow is in the game. According to the latest devstream, he's going to talk to the coders to make sure what is supposed to be happening is happening. Thus it is a bug that it isn't. And if it isn't in Beta 5, then we need to let them know that it is still a bug.
Yet each time we try to tell the devs that production/research isn't working as intended, it's immedately presumed we are talking about multiple things at once.
I can't imagine why. No. Not at all. 
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tl;dr: For the Love of Whatever, if you want Production Spillover stop talking about buiding more than one thing at a time. Please. Pretty please with sugar on top. 