Perhaps there needs to be an Appendix Shooters Association.
It's not just mean old IDPA.
USPSA does not allow appendix in Production where most of the usual crotchguns would fall.
Local organizers smarter than Bill have holster provisions.
GADPA does not allow appendix.
ASI does not mention appendix but says the gun must not be pointed at shooter or bystander during holstering or draw. Shoulder and cross draw rigs are not allowed.
MCTS says "belt holster" but does not mention appendix although shoulder and cross draw rigs are not allowed.
3GN does not allow IWB.
I have seen two AIWBs in matches. One guy was allowed to shoot from one in an IDPA match. I don't know why, he had a foreign accent, maybe he was on a Visiting Expert visa and showing We Colonials how it is done in Ruritania. His draw looked ok out of the holster, I thought his presentation was bringing his left hand forward of the muzzle but the SO said he was not sweeping himself. The reholster was marginal in terms of sweeping himself.
The other at a USPSA match where it was allowable in Limited. This person was wearing an IWB further forward than most AIWB aficionados, which put his normal draw very close to the 180, and sweeping the crowd on a stage that had a start line at 45 degrees. The RO was his buddy and would not call it. Thankfully we have not seen this genius again.
Oh, yeah, there are ranges - not sanctioning organizations - that do not allow a SERPA holster, either.