Add expression:PXY2LX, PXY2LY in Board plugin, These could get logic X or logic Y from physical x and physical y. For example, get logic X and logic Y from current cursor position. Return (-1) if position is not in the board.
I'm having some problems when the NPCs are wandering, they happen to step on the tiles that are supossed to have rigid behavior (I know the tiles work fine beacause my player collides with them) and on you Adventre capx example, I can't find anything else about this :/
The collision and moving are handled by grid move behavior in this case. User could put solid behavior at tiles or chess, the grid move behavior will check them automatically. Or you need to check collision by yourself, you could get the UID of target tile by "board expression:LXYZ2UID". Then get tile instance with this UID.