True, this is the only flaw I found of using this method. The tile should most probably have masking like a vine in the middle of it. However, wallclimbing will always be an issue in this system.

Btw, No Fire Zone sounds like a good event to edit imo, if you want to achieve such an effect. What you say sounds like a "No Jump Zone", where pressing one of the keys is ignored - same as No Fire Zone. As I'm used to say, I'm not a programmer though, don't listen to me.