Hi Dite, good to see you back. I think your “struggle” is very common. It’s kind of a problem in how we are communicating the Coach Jack workouts for outdoors, we will improve this.
Coach Jack workouts have 4 components. Warm-up, main work, secondary work and cooldown. The only one that requires much focus on intensity is the main work. Ideally find a semi-consistent place to do your intervals, this is pretty hard offroad but do the best you can. So 3 minutes at 100% of FTP really more or less means 3 minutes of zone 4. If NP works for you for these main work intervals that is totally fine. Could be as simple as zones if you prefer. Regarding secondary work I would just say if you are riding more than 3 days a week try to keep most of your secondary work in zone 2 and if you want to go hard core aerobic, do zone 2 HR for your secondary work and put it before your main work as much as possible.
Does that answer your question?