Sorry to read of your accident. Hope the damage heals quickly and you get to work with your new wide view soon. Just to stir the pot I would suggest a different approach. Something in the way you see motivated you to buy this attachment. I felt that way after seeing Lois Conner talk show her work using a 7x17 in China. I would encourage you to give that motivation complete freedom and discover what results. You can always make adjustments later.
A starting method often suggested is to take a piece of 8x10 cardboard and cut a hole in the middle the exact ratio of your gear. In my case that is 7x17 or a ratio of 2.43. I would then look around at the subjects you like and see what fills that hole. This is just to start giving you the feel of the camera’s view. You will probably discard the tool as you get the feel of the composition.
Michael Mutmansky and I spend a half day shooting an abandoned greenhouse with his 7x17. I asked him to proceed as he would but to say out loud what was going through his mind. As with Jim Noel, his most used lens was 300mm. A normal lens would be 466mm or so. He also said that when composing be sure that there is something interesting out to each edge.
I am working on a 100 image submission for a book on the OH & Erie canal. The locks are very panoramic, 90 feet long and 15 feet across. At about 60 images my most commonly used lenses have been the 300mm and the 600mm for close detail on the opposite wall of the lock. There are four samples in my gallery.
Enjoy whatever works for you. Frankly I think I would much more enjoy RobertP’s 8x20 nudes using the vertical orientation than my canal locks.