im with jetman...wot happens when u got a run of 8 boards and you need to get it flat? youd need to be a bleedin giant octopus!!
what happens if the walls a mile out??
i used to use expanding foam all the time as a window fitter...even stuck window boards on with it...and cappitt boards (the cover cill 9mm shite)...so, you gun the bricks/existing windowboard plonk your 1800 bit of cappitt on it, job done...go do next one, and the next one...then you go back to the first one to trim the rest up to find it floating 4 inches above where you left it ;D
wouldnt trust it at all..no chance...
i liked the look of those drywall bullys tho...like a pump action adhesive applicator...i just couldnt be arsed filling it up twice per board tho...