I'm building an indoor climbing wall out of 3/4" plywood in a finished
space. The wall will be well-secured to beefed-up framing. How do I
avoid rough edges/splinters, particularly at the butt joints between
plywood sheets?

My joint finishing options a
1) Do nothing, simply risk splinters (it's decent grade plywood)
2) Tape/mud as you would with drywall (I doubt it would hold up)
3) Leave a 1/8" gap and use some T-molding between sheets (not exactly
the look I'm going for).

Any other ideas? Besides NOT building a climbing wall, that is?