It is IMPERATIVE to be able to see the structural integrity of yard trees. In the last 7 years I've removed two large white ash trees from my property. Both because of splits at main branches. IF either was covered by ivy it would have been impossible to see this and poof, by one one would have fallen on my house (or Mustang! or wife). Now if its in a naturalized area let nature take its course to some limits. I suspect though natural control measures which limit the spread of vines in woodlands are not present in your yard. Fewer vine eating animals, less fire for a couple. So you'll need to play the control part or else the vine stands the potential to take over.

I'll gladly send you my list if you have any to share.

How fast anything will fill in depends on growing conditions, particularly water in TX. Can you give information on that? Or you may want to ask on your regional forum. Since this get to 15'-30', 3 seems like overkill to me on a 12' x 8' screen. If it's a really substantial support I would think that you wouldn't want more than 2. If you want some repeat bloom beyond spring, look for Bignonia 'Tangerine Beauty'.

Hello! I’m looking to cover the entire back wall of a detached three car garage with crossvine. Northeast exposure. Should I go with Jekyll or Tangerine Beauty? Another variety? Thanks so much!!