I didn’t have time to read all the responses, so perhaps this has been addressed, but I think your comment that you don’t have the time and patience for a lot of work on this is both telling and concerning. For your safety and for potential riders you may share the ring with in the future, you should be addressing this and not be worrying about what small show you can go to and pin. If you don’t have the time and patience, enlist the help of a respected, patient local trainer who can put the miles on this horse by taking him to group outings (hacks with a local fox hunt/cubbing, group conditioning, shows where s/he has other riders and can exercise him in the warm up ring, etc.) If you don’t have time, patience, and the physical ability to do this, you and your horse would be best served getting help. That’s why there are trainers! Patience, miles, appropriate experience building activities, expert half halts, and slowly building up to shows would be a good start. Fix the problem at the root, not just with a change in tack like martingales (not okay for flat classes) and bits that you may not even be able to use at a show (switch to dressage and no twisted bits, etc) since shows appear to be your end goal. If you’d like to post your city or region, I’m sure there are plenty of helpful people here who would be able to personally recommend a trainer to you. Going to shows should be the icing on the cake that comes after putting the time in to get ready and be safe. It isn’t courteous to other riders to zoom around a show ring, so that isn’t where I think your training should occur.