Best way to manage this unruly den nobile hybrid

[cuckoo]

This is about 4.5 years of growth from a tiny bit blooming size plants with 4-5 small to medium sized canes. I had put it in a hanging basket next to a sw window with supplemental overhead grow lights lights in the evening. Some leaves appear to have sun damage while a bunch of new canes appear to be diving downwards leaving old leafless canes exposed in the middle. A second round of new growth is emerging and they are likely thankful for sparse middle to grow without jostling. There was two rounds of bud development this winter, the first giving abundant blooms but the second later round turned out to be keikis on some canes and shrivelled up on others. I am concerned that those newer canes have now lost the ability to bloom from those nodes while not even producing any kiekis. So, what's the best way to optimize growth, flowering and display