To Gregg. It is common knowledge that PCs calcpro is innaccurate with this projector(which is why I even said I didn't look into it further).
The largest I've personally seen with the 55 was a 130". Firing on a Screen Research ClearPix grey(0.8) it returned 12fl. Which 12 was just fine. I would assume that on a 1.0 gain an increase of another 20" would remain close.
But i've not personally run across a screen bigger than 130" where the projector chosen wasn't the 75/95.(which there shouldn't be any lumen advantage...according the "specs")