One more thing to consider changing mine pyres is the strength cap aswell. Personally cant make a minehole in my current setup due to lack of strength, which I didnt consider an issue until I just found out that there's no hard metal on cave, from this forum post.
Whilst I do like the part where you keep all information away and letting people find stuff out on their own, these kind of things are pretty frustrating.
Cya in 2 weeks when I got 100 strength to even be able to set my pyre on fire, since I can't even place it.