I suggest use only Sharpen + Deblur, sometimes less is more. Spend most of the time into find the optimal “Deblur” value that fits to set sharpen value, means increase Deblur until pixel blocks gets biger, image get sharper and gets more contrastfull. Then increase “recovery original Details” just as high as it still looks natural (most it’s lower than 20)
If its 1080p and thoroughly noise-reduced, there’s probably very little detail left to improve. I’d at least try two things: first, try Iris keeping the resolution the same, on medium quality with manual parameters so that I’d keep them as they are estimated, except 0 noise reduction of course and improve & recover set to full 100; then second enhancement Iris medium with intermediate resolution set to 1x and manual parameters with only improve & recover set to full 100 again. Next, I’d give the resulting video back to Topaz and set both enhancements to Gaia High Quality and up to 4K. So I’d at least check this double iris + double Gaia combo out.