I rode him out with Kristen on Sif. She needed to work on her horse leaving another horse on a trail ride and her horse being left by another horse on a trail ride, so we got a lot of trotting and cantering in, as well as waiting around while she went away, during which Leo got to eat some nice prairie grass.
In our forays away, we addressed right lead canter, which is a little harder for him, so he tends to ignore the aid for it as if he doesn’t hear. Probably a fitness thing. It works to put him in haunches in, or one could think to remember to use the outside leg to hold the haunches steady. Attention to keeping the outside seat bone back also helps.
We worked in the indoor with Archie and Megan for a while at walk and trot. Then we went for a walk hack down to the end of the gravel road. Then we had some walk, trot and canter work in the prairie. I see what you are talking about with the right lead. He would rather take the left, so even if your timing is right, he waits a beat and takes the left. I carried a stick (ok, a boxelder branch that I snagged) and used it once lightly behind my right leg on canter depart for right lead and then he was spot on.
This was supposed to be a cute shot of his face, but he came closer quickly and it turned into a wanna-be artsy horses-are-mystical-creatures eye shot. LOL.
I worked with Leo on the flat with Kelly on Elsa and Megan on Archie. We worked in all gaits and Leo did well, though he mentioned that the load of hay that was standing in the middle of the arena looked delicious! Then we went on a hack around the meadow, using all gaits and he was great. On the way home we all stopped and let them graze. I took off his bridle and let him eat a bunch and also hand-picked him some for enjoying back in the stall. Nice day for all!