i believe (and Tighty might correct me) that the 2.3opm start time is based on a number of things including, but not limited to:
Casino opening hours (they"re not all 24 hours)
Casino closing hours (ditto)
Licencing times (ditto)
Dealer availability (shifts & so forth)
Casino Support Staff availability (Bar persons, kitchens, valets etc)
Frankly, other than tweaking the payouts, I don"t see any over-riding reason to change much about the starting stack, structure and buy-ins.
Over-"improving" things is often the road to ruin.
What APAT has, works, let"s not fix something that"s not intrinsically broken.