I'm pretty sure the regulations support, or are being reworked to support, electronic update submissions. It doesn't make sense to have high speed changes on the floor when you can't get them across to the state in high speed.
That said, I'm not sure I agree that it's not good business. It's very commonplace in other industries to charge different fees for the same services at different times. Lunch always costs less than dinner. Even in table games, you can find a $5 table mid-day Thursday but not Saturday evening. Other than changing the game entirely, the two levers the casino has are denom and edge. Most slot games are multi-denom, so that leaves only edge. In my mind, taking a multi-line penny machine from 92% to 90% on a Saturday evening isn't much different than taking a dice table from $5 to $10. Casino games have different EVs based on location, why not time?
"In my own case, when it seemed to me after a long illness that death was close at hand, I found no little solace in playing constantly at dice."
-- Girolamo Cardano, 1563