Long story short, I was running randoms for XP to level skills up and at the last moment, I got the luck of the draw and Captain Blackheart turned me into a skeleton. Well low and behold, I did not get any XP awarded towards those skills, and I'm not even sure I got XP awarded at all for completing the dungeon. I know for a fact that I didn't get any XP for the skills because I had level 1 skills and a 150% XP buff active.
Not sure if this is by design, but thought it was a weird behavior that doesn't seem as intended. I assumed it would award the XP towards whatever skills are on whatever active bar I had at the time I was transformed. Maybe, maybe not.... just noticed it