Walter, you certainly know how to amaze, and keep on amazing us. Very nice use of a super wide lens, in fact about perfect use. As to the answer to your question, yes, a super wide lens can be meaningfully sharp.
The widest lens I have is my Fujinon SWD 65mm f/5.6, which is definitely very sharp when used well. With an angle of coverage of 105º, and using a graduated centre filter, even the ground glass looks sharp as a tack, edge to edge. However that 47mm lens with 120º angle of coverage is in another world, some serious architectural stuff could be captured with that coverage power. A bale back could be handy to help eliminate ever so slight movements getting the film holder in, even 1mm of movement would show up sometimes I would imagine.
The first time I encountered a 65mm lens on a 4x5" camera I was assisting a photographer doing an interior of a heritage listed house, I was quite amazed at how good things could be. I don't remember what the lens was, but I do know it was 65mm with a centre graduated filter and we had one room where it wasn't wide enough. For insurance we shot two negatives in a panned format, and as usual C41 was used as we couldn't get correct colour due to mixed lighting; colour was corrected on the Chromacon scanners and the two negatives electronically combined in a seamless manner. The first Chromacon machine we bought was approximately $1,000,000 in total cost, German technology at its best.
Then we had an idea and on the afternoon after a quick trip to the Camera Exchange in Melbourne's CBD, we picked up a Nikkor 15mm wide angle and an F3 Nikon body, it had 110º angle of coverage and it just squeezed the room in. We had a weekend hire rate on that lens as it was a Friday, what a fun lens that was. The 135 format lens was not used in the end for whatever reason, but we had a hoot playing around with it.
I can only imagine just how wide that 47mm lens is, definite wow factor when you pop your head under the dark cloth.