Well, I seem to have stumbled my way into fixing the basic problem with slow file saves from photoshop. Seems when you open a file from Lightroom to Photoshop, my LR preferences were set to save the file as PSD (seems a logical choice), but changing to TIFF turned a 29 second save to 1 second. Now I need to review how video in Davinci Resolve is doing. At least I have no urgent need to get faster disk performance for daily work.