I know you posted this a while ago, Aegisx, but I have just bought a Kestrel FE85C from Amazon. It is a beautifully manufactured case, extremely heavy-duty, but perfect for my application where a ceiling drop or wall mounted fixed screen are impossible. I also wanted to zoom up to a Cinemascope 2.35:1 aspect ratio and maintain constant height on all formats.
With all that said, I do find the waves in the screen distracting, but perhaps that is the compromise you have to live with if you want a floor-rising non-tensioned model. I am going to play around with some more source material over the coming days, but if the waves in the fabric are too overbearing I may return the FE and just find a way to mount a fixed screen in this non-ideal environment.