My suggestion would be something called a mine shoring. It would require wood only, and it would have a unique pattern of "safe tiles" that it supports. The idea would be to give people the same ability as they currently have with snaking, but making it an official mechanic that requires slightly more effort than sticking a pick in the wall. My basic idea is that the shoring will not obstruct player walking, and that it would extend the tunnel at least 2 squares per shoring in a cross pattern (to avoid the need for having a direction attached to them). Considering how easy snaking is, it might be more fair to have 5+ tiles in each direction covered. That's entirely up for debate.
The mine shoring would require at least 3 blocks to construct if it were a stand alone structure. Another possibility is that they would work like the milestone. Having a tunnel entrance that requires a significant input of materials (100 blocks, 10 boards or something similar), and then being able to place subsequent supports for a cheap cost (the mentioned 3 blocks ea could work if the supported distance were large enough).
Here is what ancient real world mine shorings look like:

And here is the suggested support mechanic diagram:

On top of this, mining mechanics would probably have to be changed. For this idea, mining any unsupported tile would have a chance of causing collapse. This would be tempered by caves though. Making the final "rule": Mining any unsupported tile, or any tile not in direct proximity to a cave tile would cause a collapse. This would allow test mining of caves to continue without any hiccups. Furthermore this system would be even more inefficient for mineral extraction than snaking, making true blue supports the only way to go for node exploitation.
I think this idea is viable because it still allows cave warfare and "prospecting" the slow and steady way. It would look much more authentic and bring the game's mining system more in line with the reality of the time that it attempts to simulate. It's also a simple concept, making it noob friendly. A thing that's never a downside in my opinion.
Edit: I did spend time reading through suggestion posts based on "mine support" to see if this has been mentioned before. I didn't find anything, but feel free to let me know if this idea has been mentioned before and I'll take it down.