The longer it takes the taproot to hit bottom the longer you'll have to veg an auto. I don't know how they work in hydro, but in soil you need to know that when the tap root hits bottom they bloom. Longer veg typically results in increased yields.
Any chance you or anyone else has done a sort of auto root height test? Like get a bunch of different sized/depth pots, use a bunch of the same genetics, and see around what pot height triggers flowering around what week. I've heard about that 'tap root hitting bottom triggers flowering' thing plenty of times before but never seen anyone mention specifics. I'm not asking you to do it but you do have a wealth of knowledge and may be able to point to someones journal that has tried it. It just seems like one of them 420 mad plant scientist things to test and document for fun and science.