I'm at maybe 10% completed on the skill Croppery 3. I do not think I have used any shrine favor on this skill, but if I have, it was a minimal amount as it will still take 22.5h.
None of the shrines will let me use favor to shorten it, they say "You're already learning as fast as you can!" ("You can't spend points right now")
The Completed section of the skill bar is somewhere between I would estimate 5-10% green.
I would really like to cut this down to an overnight skill rather than a nearly full day.
(edit: this is happening with a few skills, not just the one)