Beginner Gardening: Crepe Myrtle Pruning, 3 by RyanDonovan

RyanDonovan wrote:
I purchased a property last year that includes some lovely crepe myrtles. I've included pictures of a representative group of them. I have a few questions:

I would like to prune several of the trunks growing up from the ground - possibly down to 3 or 5 trunks per plant. Is there any drawback to doing this now, as the plants have started putting out new stems and leaves? Or should I wait until next season? Should I do this all at once, or only a few trunks a season over several years?

These pictures show the plants as recently pruned by my landscaping guy. They look good to me. Does anyone have advice on how they are pruned?

For scale, these are about 9 or 10 feet tall.

Thank you!