this is ace.. ive been trying to perfect my miner for awhile now.. placing blocks in front almost always fails XD you could add a brass filter on this to get rid of the stuff you don't want.. and if you want to save some resources you can use normal rails and make sure there is coal in a chest

I place a row of deployers facing up immediately behind the drills on the next-to-top row, and a column of them facing the sides one block in from each side. If I have the materials and want, I put some pointing down as well. This fully encloses the tunnel as you mine. I like the cab in back, though. If you have full netherite diving gear, you're immune to lava as long as your backtank has air, or make a magma slime backpack with the Traveler's Backpack mod to not have to worry, either. Mobs will be your only concern after that.