The minimum lens throw ratio is 0.2 x image width. Yes, all projectors with minimum 0.2 lens throw ratio are all compatible with the Insta-RP/Insta-RP2.
While one may project images on the front of the surface of the Insta-RP/Insta-RP2…the quality of the reflected image may not perform equally, and therefore reduce the overall fidelity of the picture .
Yes, the Insta-RP film will indeed function perfectly on a curved glass setup. Below are two examples of such installations: