Fantastic work on the ascent of Clean Break, it’s been years since I climbed in that area so I looked up the route, sounds amazing!
A little help with your questions:
It sounds like you’ve identified a few places to focus.
1) head game you are already working on, well done.
2) better uphill ability on approaches – this can be a game changer, the more efficient you are at uphill with a pack, the less fatigued you’ll be before you begin the technical climbing leaving much more energy for the climb itself. Leading of course to having the stamina for harder routes.
3) climbing harder with a pack on, which you’ll want to train for specifically in addition to the aforementioned in #2.
I’d jump on #2 now, as it will take time to build more of an aerobic base and this is what UA is all about, correct ADS and loads of Zone 1/2 training.
Begin by spending a couple of days a week at a local hill with an alpine climbing weight pack and carrying it uphill at or below your aerobic threshold. Again you’re building for next season so keep this up through the winter.
Since we can’t train for and change everything at once maybe your next step since you’re in the groove with the upholding would be winter difficulty training for climbing.
#3 beginning a winter climbing strength training program would be fantastic, as well as adding in training with a pack on if you aren’t already. Wear your pack (after warm up)Bouldering at home, if cragging lead and do TR’s on the same route while wearing your pack, and when you’re in a training cycle with your hangboard adding a bit of weight to that as well, you want to be cautious to build up to this.
All this will lead up to a stronger and more efficient you come next season.
Good luck with all and enjoy the climbing! The list does just keep getting longer doesn’t it ( :