I've used just about every concept noted so far and then some all depending on the specifics of the application, I believe it is critical to know what you are trying to do before deciding how to do it. So a wild idea here, but how about defining the application as completely as possible first? How are you going to use projection? What type of sources and media will you be presenting? Would any install need to be permanent or, conversely, does it need to be portable? How large is the room and do you actually need viewing in all of it or only part of it? Do you have a full
fly tower where you could fly out a truss type screen? All of these factors and others may be relevant to determining the approaches that are optimal or even
practical.
I typically avoid mounting projectors on battens. Not only are there potential issues with movement as already noted, but depending on the line set
spacing there can be clearance issues. I have often used battens to hang a truss type screen and masking, sometimes with the ability to tie down the screen or
batten to the floor to limit movement.