Thanks. I might persevere, but I'm not sure the tonality is to my liking with Fp4+ but I will see what some tinkering or a change of film does. I should add that my expectations relate to prints that will likely go up to 40-60". I generally don't like Fp4+ and DDX as a combo in other formats and due to the limited number of emulsions available in 5x7 it made more sense to try another developer than change film. I will try Xtol, changes in DDX concentration and dev time and if all else fails, try another film. I agree that the grain has a bit more crispness with DDX than Xtol (with my smaller formats this is noticeable) but for scenes with very smooth and creamy tonality I was not that pleased with the DDX FP4+ look. I guess I will need to experiment.
I would ideally like to try to find Foma 100 in 5x7 as this film, IMO, has more pleasing tonality than Fp4+. I've only seen it in 5x4 and 10x8.