yes, not something that BFTA can change quickly other than 3 sessions instead of 2.
If there are 3 per lane and they all (typically) shoot under 2mins and allow for some swapping over then it would be approx 8mins per lane (3.5 hrs for the session plus whistles). Re-painting depends on number of volunteers. The time it takes for a group to meander from lane 25 to lane 1 divided by 8 is approx the number of feeder groups (1a, 1b, 1c, etc) so not more than a couple would be my guess. so 81 shooters, 162 for the day. Start 9:30, finish 1:00, paint, second session 1:30-5:00
If there were 3 sessions of 2 per lane then my sums say about 2.5hrs for the course but you could add in another feeder group, say 56 per session or 186 shooters for the day. Start 9:30, 12-12:30 painting, 3:00-5:30,paint, start 3rd session at 6pm, finish 8:30 .. in the dark at present.
I don't see how you can get 200 shooters (9 to 10 hrs) with the current 2mins per lane plus unknown times spent getting settled before the clock starts.
Earlier starts would help. Those staying locally could be the dawn patrol :-)