Longer maintenance plan that takes into consideration the athlete's constraints

I currently have a limitation with the available training plans, I am looking for a maintenance plan that I can define without an ending date and allows me to add constraints in order for the planner to take into consideration when choosing the workouts.
My example, I am currently pregnant which essentially means that I can’t do workouts above zone 2. I can’t raise my heart rate above 60% of my maximum.
Currently only the recovery training plan suits this but it is only 3 weeks long.
The idea would be to have a maintenance plan where the user can define the duration and their constraints.