Q.Late Pruning of shrubs
Late Pruning of Mock Orange and Deutzia Scabra – I realize that I am too late. However, I planted both 2-3 years ago, and both are growing very well. This year the Mock Orange had a beautiful display of white flowers whereas the Deutzia still has so far not! I realize that I should have pruned both after flowering but didn’t. Can I do anything at this late stage?

Certified GKH Gardening Expert
It is possible to prune your plants back now without hurting them, but this will remove the flowering wood, so you won't see any flowers next year. Your other option is to wait to prune them next year. Deutzia can also benefit from the removal of about 1/3 of its stems down to near the ground. You can do this anytime, and it will encourage more healthy growth the following year.
Here are some possible reasons your Deutzia may not have flowers yet:
https://www.gardeningknowhow.com/plant-problems/environmental/plant-not-blooming.htm