What are people's thoughts on making the mine support beams last more than about 5 hours? Maybe have them last a couple of days?

Why? Theres only a couple places you need to mine to.

*Edit* Sorry, I just read my comment and it comes across very snarky. Please help me understand the basis for your suggestion. Is there somewhere particular that you use the beams?

I use beams in mining part of Lost Cave, so you have an easier walk the other runs you probably do when done with one round. It's an easy place to get stat scrolls at lower ranks, and not having to mine that part, makes life easier when going more then 1 round.

Like Sigtyr said, it would be nice to place beams to have those mining runs be a bit easier

They can be repaired easily. Maybe that is already enough?

Wow/

I remember repairing mine beams in the old Astonia.
That brings back some memories.
I did not realise they lasted 5 hours.