My experience has been that if there is a problem area, you only really discover that when you are working on a piece you want to play. If you get to a difficult section, you might shorten that section so you are playing it “as an exercise” until mastered, but the goal is to learn the complete solo or song.
In fact, if you can’t perform a section exactly as recorded, its much better to simplify or replace that part (temporarily) until you get it. If a song is good and the player doesn’t do the solo 100%, thats much better than if he never gets out of the basement.
One of the biggest regrets I have is spending significant time on exercises. For me it created a mentality where working on exercises was"productive", when in fact I really wasn’t developing musical vocabulary or repertoire.
I can learn to play any basic rock song in short order. I’ve learned a handful of Satch songs note for note and some Megadeth solos. Thats about the upper level of my ability. I’ve practiced AP and sequences for hundreds or thousands of hours. (same with arpeggios and sweeping) I have endless variations of exercises, sequences and ideas that aren’t fully developed musically because they came from exercises. You get good at what you practice.
If, instead of working AP exercises and sequences, I had been more focused on YJM songs, I would have them in my repertoire. Practicing things in isolation doesn’t guarantee you can actually use those things.
At this point my advice is to spend about 40-80 hours (top) on AP exercises, just enough to intellectually know the kinds of things you will encounter, and then focus solely on songs. If you cant do the song at 100% speed, just slow it down and learn/record it at 75%. Eventually it will reach 100% speed.