Doing any ride, particularly an indoor workout, should reward the user, not provide negative feedback by dropping their progression level.
If your threshold PL is 5, and you want to be conservative after time off, and do a workout at 4, completing that workout successfully will end up with a reduced PL.
On the other hand, doing no riding will keep that PL at 5, unless decayed over time. This is classic negative feedback and should be corrected, if possible. But I’m not sure how.