Done some testing in a 'real' environment now, and it's a qualified success. It handles the FX send and return plus the channel control without a problem, even over 10m of cat5. However the disappointment is that as soon as I add the input from the guitar it squeaks and feeds back like a bastard. It just about copes over 1.5m but is unreliable over a longer run. If I had any electronics knowledge at all there'd probably be an explanation.
So I will be using it live, as I hope it'll reduce setup/breakdown times. Pics of the final setup to follow...



