You shouldn't even be using UltraHLE, because quite frankly, it's older than ancient. Also, UltraHLE only runs on Glide, so unless you can get a Glide wrapper working with it, don't even bother.
Odds? Not very good if you ask me.
I played OoT on it many years ago when I had a Voodoo card, but I never played past Kokiri Village and the first room in the Great Deku Tree. IIRC, everything seemed fine on the surface.