This thread is relevant to my interests. And my experiments might be relevant to the OP.
Since there's no realistic way to make my 1 bedroom apt bird safe, I decided to create a safety zone around the cage so the birds are both contained if they did get out of the cage and also have a flight zone that's larger than their cage.
Since I'm not really handy I made mine with PVC pipes (and, as a result learned to use an power drill and screwdriver for the first time - and now I really do want to drill holes in everything) and covered it with a thin mesh, like insect proof porch screens. It would have kept them contained if I had had an escape, but I quickly realized it wouldn't make a good flight zone as 1. I doubt they'd have been able to see it well so I would have had bouncing Bourkes. And that sounds funnier than it probably would have been. And 2. they wouldn't have been able to grab onto it, which in their first, probably at least somewhat skittish explorations, might also have been bad.
The good news is it, or a very similar product was recommended by someone who knows what they're doing, it's relatively inexpensive and it's also relatively lightweight (which matters when you're trying to wrangle it in significant lengths).
The challenging part is that it only comes in (that I've found) 2' or 3' widths, which means that for a cage that's a bit over 6' tall (note to anyone else making a cage with PVC, every fitting adds length to the structure) needs 3 rounds. (If I had it to do again I probably would have run it up and down instead of long-wise, but doing it this way seemed to have the advantage of fewer seams). It's all tacked in and now I'm planning to run a rope border securing all the joins - basically sewing it together with twine.
One alternative I did find after I'd started attaching the heavier weight mesh (and here's the part that might be of interest to the OP) is a lighter weight mesh from the same mfr. This was primarily of interest to me because at 14' wide I could just roll it around the inside of my 6' x 8' x 6' (plus change) enclosure, trim the excess height from 3 sides, use the overhand of the 4th side to make the roof. With a few zip ties and probably some snap clamps, Bob would have been, if not my actual uncle, at least a close friend of the family.
I didn't just go ahead and swap in that mesh, though. My birds are Bourkes, and not noticeably strong or particularly destructive and this is intended to be for supervised time, not their main home, so, I wasn't worried about them chewing or tearing through it. I also wouldn't worry about them getting tangled in it as long as it was snuggly secured so that it was taut. What I was worried about was whether mesh that light might tear up their feet if they did use it to grab onto.
Since I've already got the heavier mesh in place, I'll just finish it up with that, but now that I have the lighter weight mesh I do wonder if it would work the next time I make an adjustment to their flight zone.