I’ve been showing with a roached mane for years! Started with a horse who had a very thick and unruly mane that I French braided for a while, but it was one of those manes where it would just unravel easily. So I pulled it, and we did NOT enjoy that process, so after a year of that, I just took it off - very liberating! This was back in the 80s, and we did a bit of jumping, a bit of everything, but I DID show at rated shows like that. I did it to my 2nd horse too, because he also had a thick, unruly mane. He had a magnificent neck, and I actually got a lot of comments on how “cool” his roached mane was - several people called him the “Chess Piece” or the “Roman War Horse”. He won a lot of dressage classes, so I don’t think the judges minded.
Then my next horse had a LONG mane, and when I bought him, the seller actually requested I not roach it - since it was an easy French braid (and STAYED braided quite well), he kept his hair.
My mare I ride now has an awful mane - not only is it THICK, it is spikey! Very hard to braid - spikes pop out everywhere. I had a professional groom do her for a Symposium this Spring, and she asked me “How do you braid this mane!”. That was the last braid job - I buzzed it, and we showed all year with a roach - again, liberating!
My feeling - your horse needs a good neck to pull off a roach job. BUT - you can shape the neck with how you cut the roach. As for getting on - I don’t ever get on from the ground. I keep a mounting block by the barn, and I’ve trained my mare to stand at just about anything -at shows, I stand her up next to the trailer and get on from the “step” in front of the trailer door. I’ve gotten on from retaining walls, stumps, etc. Much easier on my horse’s back AND my back.
Here she is:
http://i146.photobucket.com/albums/r264/friesiansport/SVEJuly2016-1_zpsvsot0zsg.jpg