Seems like it might be repairable with seam tape. Using monofilament was a bad choice on the part of the manufacturer. If the loose ends are ironed down flat and covered with tape, they shouldn't poke you anymore.

It's true that wool jerseys were generally worn with t shirts underneath, unless it was a really hot day. I was never really bothered by scratchy wool, but Merino wool was always nice to have.

FWIW I wear my Kucharik wool jersey all the time with no undershirt. Feels great. No writing on it but that's my preference anyway.