Fretting hand pinky question

I’ve recently tried to analyze my fretting hand more closely after finally getting my picking up to a level where I can just polish my current mechanically-correct techniques for more speed. What I’ve struggled with is pinky endurance. The first knuckle, about 1/3 of the way up the pinky sort of “locks” or snaps ever so often; this results in dull and mild pain and a general feel of losing speed.
I can use my pinky somewhat in licks, but the problems start occurring when using my pinky for trills or Yngwie-style licks, like the harpsichord intro to the solo in I’ll See The Light Tonight. I think I’ve narrowed the solution down, and it’s focusing on the part of the pinky which I use for actual fretting. I’ve mostly used the soft pad of the pinky instead of the tip, so now I’m trying to focus on curling the pinky more and using the finger tip.
The reason for this post was to ask for how you guys use your pinky when fretting: do you use only the tip, the pad, or both?

The pad. I can’t think of a situation where I’d use the tip (I would try to avoid this situation!)

Mostly the tips on all fingers, but in some cases I’ll use the pad too. Like a situation that requires barring, or something like that.