Having cantrips only create surfaces if targeted at the ground seems like a fair middle ground. Firebolting an enemy is a normal 1d10. Firebolting the ground leaves a little flame patch. I'd also be fine with full 5e, no surfaces from cantrips at all, but different behavior for targeting ground vs enemies seems like a compromise.
+1
This. So much this.
Larian could with this put their efforts into an environment thats actually interactive instead of the generic tiles with a different texture. In some areas only certain surfaces should be possible (no fire in a blizzard) and in most only last a very limited time. In others, they should be more powerful. Like a fireball into a barn full of hay. A short strong fire, that leaves back ash. Ash that actually inhibits putting flame surfaces on it.
This could be easily paired with missing a target. Failed attacks interact somewhere in the direction of the target with the environment.
