Have you tried using the T-S lens with the Scheimpflug principle to obtain greater depth of field? This is one of the best features of view cameras, and I would think any tilt-shift lens.
Yes, tilt shifting for frame lenses on a full-frame camera can lead to heavy vignetting. This won't be a problem if you use this on an APS camera with for-frame lenses and even using for-frame lenses on a full-frame camera like this; it depends on the lenses. I have some lenses that don't Vignette at all