Definitely doable. I will get it worked out, one way or another. Any help is bonus.
The collision sphere can be invisible, so if mountain height is a problem I can just make the sphere extend out over the tiles a bit so that it isn’t a problem. It will be one of those things where I spend a lot of time clicking around a tile hundreds of times until I am sure there are no edge cases that can become a problem. Theoretically I could even use 2 and calculate the angle between to figure out where the player meant to click.