A compromise — #22 of 31 Flannel ranks #22 of 31 fabrics for chafe resistance. It is a middling fabric for this. Ranked with a smooth-fibre bonus plus low weight and breathability. The top pick is Silk.
Flannel measures 58/100 for breathability, 12% moisture regain, 80/100 warmth, at 260 gsm. Chafe resistance rewards a smooth, light surface: Flannel has more surface texture at 260 gsm.