I have a rose tree and totally missed pruning time this year.
It is already flowering but the plant is very leggy (and also has black spot that we are treating). At this point should I just wait to do a light prune in the fall (Sept. - Oct.) and a hard prune next year in early March, or should I still prune it now?
This year it was easy to miss the earlier pruning window because the weather was not very inviting.
You can still prune, if you like. It will not kill the plants but you will sacrifice blooms and set back flowering. However, the result will be a more compact shrub. If the idea of losing the blooms isn't what you want for your yard, then follow your earlier inclination of light pruning in fall and harder pruning next spring.
I'm including an OSU publication below on "Controlling Diseases and Aphids on Your Roses".