IIRC Hyperliquid currently relays orders to validators, i.e. can see if these delay or censor them.
The dYdX approach was to compare each validator's execution to what trusted nodes would have done.
Jitter was expected, unusual divergences penalized.
So this seems similar, but the next evolution is not-so-clear.
There's a few approaches:
(1) Know all orders and penalize if any are missing.
(2) Don't know all orders but know how validators operate (e.g. TEEs).
Most DEX users will not notice when their orders are delayed or front-run, i.e. need protection.
It's easier when users are sophisticated and can impose penalties directly.
For example, PBS block builders will pull flow if their blocks are not merged appropriately under multi-party block construction.