@matt this is SUCH a common fear! I actually got stuck in this when learning the HTTK sweeps. I focused on them SO hard, that I actually got sloppy with my other parts. To answer your question, it is NOT a bad thing (and actually a good thing) to do the exercises for the economy picking. Because let’s be real, if you JUST do the economy picking for THAT song, all you’ve really learned is that part of that song. Right? But if you apply exercises with that technique, learning (or writing) countless other solos that incorporate that will be MUCH MUCH easier!
My advice, is go over the easier parts of the solo at least a few times a day. And I mean starting from the BEGINNING OF THE SONG. Believe it or not, you should work up your endurance to get to the solo and then it’ll work out the kinks of the nerves of the hard part coming up. Try your best to get through the hard parts. And then afterwards, focus on the tricky parts over and over again. I always like to give the advice “You can only play a solo as fast as you can play the hardest part.” Even though I was really good at 99% of the HTTK solo, I bombed the sweeps. So I’d play the WHOLE solo as slow as I could do the sweeps. It helps encourage stronger inflection and transition skills.
I don’t know if these are things you already do, but if not, I hope it helps! I can’t wait to see your progress, buddy!