I don't feel it is extreme, I am a member of a Pentax 6x7 group there that is specifically for non-cropped images. I find that valuable to be able to see what the lens actually does in terms of DOF and FOV. Cropping alters that assessment capability.

One possibility for beating the rules, as it were, would be to start a discussion thread inside the group and post your digital images/walk-through on the Pentax film back conversion inside the thread, rather than submitting it to the pool of images in the group. Quite like you wouldn't submit a digital-captured image to the galleries here at APUG, but you could start a thread and submit digital-captured images describing the film back conversion therein.