Back during the C-17 maelstrom, I was the club IPSC director at Trillium Sport (later USSR/Grange, etc)
We had a huge number of people interested in the BB, because there was a possible exemption for normal capacity mags.
With only one weekend a month available at most, and a maximum of 9 shooters per course, we quickly wound up with a 80-90 member backlog. For months, the courses went well because people not equiped or ready for the course bowed out making room for those who were ready.
After a number of months, we hit the bottom of the talent barrel. After one particularly frustrating course where 3 students lacked the basic skills to finish, I called a halt to the practice of just signing up. Before you got on a course, you had to meet me at the club and demonstrate that you could hit a 12 inch target at 25 yards in single and double action (if applicable). If you could get 80% or better hits, I'd give you a spot. If you couldn't, you waited until you could.
I was told recently that IPSC Ontario has taken a dim view of any pre-screening of students. If it's true, while I can understand not wanting to needlessly exclude interested people, it doesn't sound like a horrible idea to make sure they can hit the paper before putting them under the stress of the course.