I realised the Tilemap just needs two things
- Select from dropdown all tiles (besides excepion tiles) behaviour from limited list, ie: solid, jump-thru, none
- per-tile exception behaviour from same list (solid, jump-thru, none)
Thus solving the problem of people applying any old behaviour to a tile, and not needing three tilemaps or more for different tile states.
BONUS suggestion: built-in animated tiles, per-tile, define the range of consecutive tiles as frames and speed.