What about stretching in between?

Like you, I abandoned pre-workout and post workout stretching without any ill effect.

I often stretch in between though, and have found it can be effective in relieving chronically tight muscles. For example, I had a 'permanently' tight hamstring that I fixed with 30 seconds of targeted stretching per day for about a month.

I use it for either imbalances, or for soreness from weight-lifting. However, I'm less certain of the usefulness of what I'm doing compared to my hamstring fix.

Those stretches were provided by a physiotherapist, and worked very well. My previous hamstring stretches had achieved nothing. The ones he gave me were generally dynamic stretches.