I know that my answer will probaby not satisfy you. Having said that, here I go.
For the last years, and more so after I became a MELT instructor, I have begun to look at stretching in a different light. Stretching feels good, and I do it some myself, but in our dysfunctional world of little movement, it is incumbent on us as trainers to look at the cause of tightness.
My MELT answer is that it is the connective tissue that is dehydrated and needs to be lengthened. Here – after having self-assessed – the client is encouraged to treat the tighter side an extra time.
At the same time, a tight muscle may be an indication of joint instability, and all the muscle does is protecting the joint to move into an unstable range of motion. Any stretching here would do more harm than good because it would be more important to identify the cause of the joint instability rather than coaxing and cajoling the ‘tight’ muscles to stretch.
I believe that as long as you are clear why you want to stretch, the answer to your question is a unambiguous: it depends.