should only taake a leaf off for a specific reason.. like too much of it and rh can't keep up, or preventative to avoid mold and such...
you can always take a leaf off and in most cases the plant is going to go one with its business as usual. Vegetative growth stops a few weeks into flower, sometimes longer. So, you want to be more careful around this stage and later because nothing is growing back. No mistakes will be undone.