I'd settle for once per second. There's a lot of very fast trading nonsense which I've only heard defended with the "liquidity" bogeyman.

A sealed-bid uniform-price batch auction seems like the right action.

Even once per second seems like overkill. That interval would still largely just facilitate the weaponization of exceedingly low information latency.

30 seconds seems reasonable, 1 minute better, and 5 minutes still better. In all honesty even going as long as 30 minutes should still facilitate all legitimate purposes.

It's your God-given right as an American to get millisecond level price discovery. Trading delays sounds like Communist bureaucracy.