LH457 LAX-FRA seems indeed to depart with a 3 hour departure later today (due to late incoming aircraft from FRA - LH456 will arrive LAX with a delay of 3+ hours)

EDIT: Yes seems to be eligible to comp. for delay. EUR 600.

Odd that LH hasn't rebooked you via MUC to depart of LH453 to MUC (A380) with onward connection to LH1692 MUC-PRG arriving PRG at 4PM tomorrow which would have exempted LH from paying any comp as the delay into PRG would be less than 3 hours.