James:
Adding ME training to your program will help your uphills and downhills. I’d start with our GYM ME progression (see the ME article). Do this 1x/week along with hill sprints 1x/week for at least 8 weeks. After 4 weeks progress to doing the hill sprints with 10% of BW added. Keep them in the plan till 2 weeks before the race.
After the 8 weeks shift the ME to long weighted uphills. Use at 10- 15% grade and use 10% BW and run as much as possible. Workouts will start 2×10 then 3X10, then 3×15. Donde 1x/week. Stop all this ME stuff 12 days before your race.
The next training cycle you should start this early and you will get more benefits.
Scott