Scripts _must_ use a fixed 25 ticks per "second".  Making this depend on an external variable will introduce desyncs and other timing inconsistencies.

Consider a simple script that makes a player lose after 30 seconds.  If the player then loaded the replay and set the playback rate to 200% (via #4233 or Settings.Timestep = 20) this event now needs to occur after 15 seconds. This function would make that delay 30 seconds regardless of the playback rate, which would make the replay desync because the player didn't lose when they were supposed to.