Well you broke that pretty much instantly! Hopefully V5 patches that. Yes, you are meant to use the Miner in the intended solution!
By the way, how does Heaven and Earth perform for you now?
Can you double-check that Bird Knight is correct in the NeoLemmix pack? The exit doesn't seem to trigger on the experimental version of NeoLemmix. Other than that glitch, here's a replay for V2 of Bird Knight that uses no diggers and only 5 miners and 3 climbers, which is as efficient as I can get it tool-wise, at least so far.