Carpinus betulus "Rusnak" new foliage
It took about 20 days to decent new foliage emerged on top of the tree after defoliation. It will take few days to harden and mature. But I can see some new branches and it was the purpose, improving ramification. You can see on comparison of leave size between pictures of bottom branches which were intact. Bottom branches need thickening to improve structure, so I will leave sacrifice branches until autumn to gain sizes. They already have about 4 mm-5 mm. I think they could gain few millimeters more. You have to sacrifice look of your bonsai in development if you want to build proper structured tree. I think if you are trying to keep underdeveloped tree in show-able stage you slowing down its development. Try to resits to cut all branches on "proper" length and let nature do its work. It will pay of in long term.