THis was my plan also. Buy a cheap roll up and replace the material with AT. The only fault would be because they are non tensioned they would/might wave or wrinkle. I don't have my projector yet, but I'm trying to figure out a non temporary AT screen solution before I do. I'd hate to make a tensioned frame AT screen and have to move it out of the way to watch my RPTV.
If you get around to swapping out the fabric, let us know how it goes.
If you get around to swapping out the fabric, let us know how it goes.