First horse ride upon loading a save/instance doesn't apply a modded FoV value. This fixes that.

To change the FoV, open horseRiding.ws & change both "camera.fov" values to your desired FoV (mod is 110, vanilla is 60). Make sure no other horseRiding.ws file exist in your mods folder. This is mainly a modder resource since I hadn't encountered the fix before; all I did was add another "camera.fov" under mounting since vanilla only applied it when dismounting.

Bonus fix: Not sure how common this is but I had a bug where the world would disappear & reappear whenever I changed camera pitch on-foot at 90 FoV. Turns out 89 & 91 values work perfectly fine, the game just hated that specific number for some reason.