I recently picked up a lightly used Nightfox. One problem was the lack of saddle adjustment. I don’t know how anyone would have thought it was a good idea to make a uni with the nose of the saddle lower then the back with no saddle adjustment. It puts all the rider’s weight on the narrow part of the saddle rather then the sit bones. Here is my solution with a slightly less curved saddle and nose up setting. It is quite comfortable now.
I also added a 109mm hole in the 138mm cranks and installed spacer washers on the bearing cap and d-brake adapter. I now need to improve the handlebar and figure out what to do with the brake lever.
Try a Club saddle. I recently picked one up for my daughter and I was surprised how comfortable it is. It’s a bit like a Naomi (same base I believe) but with flatter and softer foam.
I think it’s possibly more comfortable than all of my fancy saddles.
Yes I was thinking of flattening the green gel saddle also. A few years ago before the flatter saddles came out, flattening the gel saddle was very popular.