Here's a thought.

This may need a major rewrite of part of the code, two seperate commands "/laps" and "/timed" would be great. If timed was in 1/4 hour units it would be the best for customisability (1 ===> 15 mins).

This would allow e.g. 115 laps or 30 min races

Do you mean settings like:
Race length:
12 laps, with a max of 20 mins
46 laps, with a max of 70 mins

Quote from TagForce :

Do you mean settings like:
Race length:
12 laps, with a max of 20 mins
46 laps, with a max of 70 mins

Yes, and also entering "/laps 0" would be as many laps until the time, "/timed 0" would be as long as the distance takes and both at 0 would be practise.