Is it possible to grow a vine such as crossvine on top and in azaleas that are mature and large?
azaleas with vine growing on top.
It's possible, but would probably prove to be quite a headache in the long run.
"eyes"
I'm afraid that the crossvine would prevent the azaleas from getting enough sun to produce new growth and blooms. Could choke out the main branches as well. I would be wary of growing any aggressive vine near your azaleas.
How about Butterfly Pea Vine?
If you can control it and keep it from interspersing within the azaleas, such as on a lattice, or trellis, then maybe but it would probably require every other day maintenance to prevent that from happening. I have pea vine seeds if you would like to try it out. I'm just afraid of any vine growing on or in between a shrub that you're not willing to lose. Maybe grow it in a pot, near the azaleas, at first, to get an idea of the growth habit. Who knows? It could work.