[HeLiOn_PrImE]

If it causes no lag, than sure, but I would make that 0.5 seconds. The players won't be paying attention on how fast their position gets updated in mid race.
Plus, if they have a slow internet, they will experience latency anyway. I'd keep a lower amount of work for the server unit.

Anyway, how do you suggest I use your script for a stunt/race/dm/freeroam server? Included in another fs, or start with it as a gm, and build around it?

I'll look into more ways of improvement.