Is merino even the right choice for a high-sweat situation?
They may be good for no-stink, but perhaps not really the best choice for high sweat.
Some excerpts from here: https://www.reddit.com/r/MerinoWoolGear/comments/1hypbdl/sweat_merino_tmi/?solution=408ba1375196baff408ba1375196baff&js_challenge=1&token=7afd7253fec22262ff1c52b1703fe9ecdb1449b7a3925e81080a1cf08c4338c2&jsc_orig_r=
I was drawn in by the promises of breathability and easy to dry and not smelling, etc. Because I was sweating, the underwear was always completely soaked in sweat. They performed worse than my other underwear purchased in a multipack from Target for a few bucks.
My experience is, merino can certainly get wet by sweating. But that takes longer than other materials plus it dries much quicker (a few hours tops).
The main advantage I’ve found during multi-day hikes is the lack of stank. I don’t feel like a complete monster rewearing them for 2-3 days if I need to. Other than that they’re no better on drying or breathability than my bamboo cotton pairs from my experience