A solid choice — #15 of 31 Merino ranks #15 of 31 fabrics for chafe resistance. It is a good fabric for this. Ranked with a smooth-fibre bonus plus low weight and breathability. The top pick is Silk.
Merino measures 80/100 for breathability, 15% moisture regain, 55/100 warmth, at 180 gsm. Chafe resistance rewards a smooth, light surface: Merino has more surface texture at 180 gsm.