watchOS heart rate zones in exercises

My heart rate (as a heart patient) is being kept down by my meds. I cannot go over 130bpm. Doctors orders. When I look at my exercise heart rate I’m always in “zone1”. I worked my *** off to the best of my abilities. 

Can you make these zones for heart patients as well? The group of meds keeping my bpm down are called "beta blockers”. Maybe custom zones even?

Zones for heart patients? Heart patients are all different I guess. 

120bpm is quite high for me. I feel left out with my heart condition by my Apple Watch. In exercises it varies from 80-135. Over 135 is no good, I go in the "red zone”. This is not an option to set. 180 is far beyond a heart patients reach. A custom high heart rate alarm would be great.

If there are reasons for this I would like to understand, so please inform me. If I overlook something, please inform me. 

I just installed watchOS 9.2, the latest, I havent exercised since. My experiences are based on the precious watchOS.