The simple answer is that if you’ve done the ftp test properly using an accurate smart trainer or PM, and then you follow the training plan, then you’ll be working in a variety of zones that ensure you don’t over stress yourself.
Further to that, from reviewing the workouts, (and assuming you use a HRM) you will be able to see what your average HR is during harder intervals. If you know your max HR you’ll also be able to assess what % of max HR you were working at.
Rather than HR stress I would recommend considering what overall training stress your body can absorb, recover from and then continue training productively. That will inform what plan you follow and how much training is good for you per week
ETA: you say you are regularly bumping up against max HR, can you link to a recent TR workout where this happened?
You may also wish to consider your workout environment, is it sufficiently cool and do you use a fan? Overheating will raise your heart rate and lower your available power…