bleeding

I have some JM's that I'll be re-potting from grow bags to shallow wood grow boxes this spring, and wood like to do some hard pruning / trunk chops at the same time. I'd like to keep as much root mass as possible but don't want the trees to excessively bleed either. So, how much root reduction...

Hi everyone. I prune some very thin branches on Hornbeam and it started to bleed, before that I hadn't dealt with Hornbeam, is bleeding for it as dangerous as for Maple? Should I postpone pruning until autumn or after the leaves mature?