Mining "Flags" to Mark Cave-In Tiles

[Epidj]

Since Mining works by the Minesweeper Rules considering Cave-In Tiles it would be nice to be able to mark or "Flag" identified Walls so you can remove the pavement that is now usually used as markings. Just to have things spawn in your Mined tunnels. Somthing like Reinforced Walls.
Maybe just some Wooden Beams along the Wall, just enough to identify that you have it marked.
I suggest either:
1. a cheap recipe somewhere around 1 Board or 2 Blocks of Wood and have it do nothing besides a cosmetic reminder
2. Have it become a slightly Cheaper Minesupport IF the tile was indeed a Cave-In Tile, Maybe 5 Nuggets and some Wood