well, I use SS bands with along screw to connect the bands to the backplate, removing the setup and back to single tank setup would only take 3 minutes, getting it back would take no more than 5 minutes (if on dryland or the sea is calm and I am on a boat) or something like 10 minutes with high care if the sea is rough.. so it is not a big deal anyway... setting it up for the first time took sometime as I had to assemble some nuts on the tanks side, however removing it and reinstalling would be easier as I now just unscrew the nut on my back's side and thats it ....
here is a photo of the setup, I just unscrew the nut that appears under the Poseidon logo in one photo then the whole setup is free from the BC in one piece as seen in the other photo.
Those bands are normally used with a manifold, the Ultimate Velcro Bands I use I don't think are made anymore but these are Twins instructions
I made some brackets out of aluminum for about $20 http://www.scubaboard.com/forums/do-yourself-diy/243915-twin-brackets.html. Here is another way to do it http://www.scubaboard.com/forums/do-yourself-diy/246601-diy-travelling-twin-cam-band.html. If you made some brackets these cam bands would work well Highland Millworks Hi-Tension Tank Cam Band w/ Quick Release.