Snares vs Conditional Movement Spells

The point of snares is to prevent players from using their movement abilities, as such it prevents the casting of such abilities. It prevents things like Kassadin's R, Gnar's E, Lucian's E, Quinn's E, etc.

However, I feel that not guaranteed movement spells should still be castable. It feels bad when you are using a champion that has a spell that's conditional movement, but you're unable to cast that spell because of a snare. Spells such as Nautilus' Q and Thresh's Q as easy examples. The moment you get snared, you lose a key part of your kit for next to no reason other than the "possibility" of movement.

I feel like snares need updated to better gate certain spells and allow ones that are conditional. At the very least allow the casting of the conditional spells and just prevent the self-movement portion of it.