You could do the healing ground idea without using a script. Create three variables - PlayerX, PlayerY, and RegionID. Set PlayerX equal to Game Data -> Character Player's Map X. Set PlayerY equal to Game Data -> Character Player's Map Y.
Then, on page 3 of event commands, look for "Get Location Info." Under "Variable for Info," select your RegionID variable. Then for info type, do "Region ID." Under location, do "designation with variables," and make the Map X variable your PlayerX variable and your Map Y variable your PlayerY variable.
Then, in a parallel process on the map, do a conditional branch: Variable RegionID is equal to 1 -> Change HP Entire Party +9999 (or however you want the healing to work). At the end of the event, add in a wait 5 frames or wait 10 frames or something.
What this will do is track your player as he moves around the map and, if at any point he steps onto a tile that's been labeled as region 1, will recover health.
The whole thing will look like this:
