A little info on the CVar: it’s an on/off (1/0) toggle CVar enables/disables adjustment of camera field of view automatically based on gliding speed. I’d describe it as a “wormhole”/zoom-in effect of sorts on the screen when you Dragonride very fast if enabled.
I only happened upon it due to some unexpected behavior today on Retail DF after returning from playing Plunderstorm for the first time yesterday. My camera was acting differently all of a sudden, but only when Dragonriding at high speeds. It was extremely pronounced when using speed boosts, both from dragonriding courses and abilities and these sudden changes were making me sick to my stomach - literally.
Unable to figure out what had changed by browsing base UI options as the Game>Accessibility>Mount’s “Dynamic Flight Screen Effects” and “Dynamic Flight Speed Effects” toggles had no effect on it, I searched CVars by the term “fly” (using the Advanced Interface Options addon) and came upon this one. I don’t know why mine was off at first, but having it get turned on after playing Plunderstorm took me by surprise. I don’t just prefer to have it off, I kind of need to.
That all said, I am only one person and I’ve found and fixed the problem for myself, so it may well not be worth it to add an easier method to for players to adjust this setting if it’s not causing widespread issues. Therefore, just something to consider.