I suggest that any "hand" in progress at the end of 30 minutes
be completed ... i.e. the shooter sevens-out.
Typically this will not run a round much beyond the 30 minutes
scheduled, but allow for a "last ditch" betting strategy on the
part of any player at the table. (Bet-it-all on a hardway, etc.).
Theoretically this gives any player a shot, however low his stack,
at advancing, or even winning.
Any other method, in effect, ends the round at something less
than the allotted 30 minutes.
RE: MAXIMUM BET AT BLACKJACK.
I suggest that "no maximum" bet be the rule. One strategy that
can (and, for me, once DID) win a table is to bet your entire stack
on the first hand. Then, if you win the hand, play basic strategy
with a minimum bet for the rest of the round ... letting your (now)
big stack force the others at the table to play catchup.
More important, I think, is the amount of the MINIMUM bet that
can be placed, which ... in my opinion ... should be in the ground
rules.
Alternatively, allow any player to let the maximum bet of $500
ride if it wins, without restriction. Again, this makes it possible for
a player to keep doubling up and ... with a lot of luck ... have a
huge bet riding on the next hand, accomplishing "the hard way"
what I propose in the "no maximum" strategy above.
Bill Alan