My question is–how ill-fitting is the horse’s regular tack? I’m a little concerned that the owner is like, “hey, he seems to be going so much better in that saddle,” and then just shrugs and uses what she’s using on the regular. Even if he’s about to be retired within the year.
When I leased, I always had to use the tack that came with the horse. I did swap out the stirrup leathers, because I’m so short, and didn’t want to wrap the owner’s very long leathers.
I feel that it is the owner’s responsibility to provide appropriate tack for all riders on said horse. If yours is okay, that’s wonderful, but it’s not your responsibility.