You can enable caps for box colliders by changing a line in tk2dTileMapColliderBuilder -
from:
int[] indicesFwd = { 2, 1, 0, 3, 1, 2, 4, 5, 6, 6, 5, 7, 6, 7, 3, 6, 3, 2, 1, 5, 4, 0, 1, 4 };
to:
int[] indicesFwd = { 2, 1, 0, 3, 1, 2, 4, 5, 6, 6, 5, 7, 6, 7, 3, 6, 3, 2, 1, 5, 4, 0, 1, 4, 0, 4, 6, 2, 0, 6, 3, 7, 1, 1, 7, 5 };
But there might be a better way of doing this - since they're box colliders anyway, you could probably use:
GetTileIdAtPosition( ... )
and GetTileInfoForTileId( ... )
All you need to do is store some identifying data in the data tab - eg. 1 in int value to identify solid tiles, and you can work out if a tile is solid or not. Much much more efficient than collider caps, esp so in terms of number of collider polys.