I fully agree this software is fragmented.
I mostly use Gigapixel, there is no good wrokflow when I taking the exported image into or from Topaz DeNoise, Sharpen, JPEG to RAW has resulted in numerous unwanted effects and the image gets worse effects that seem to get amplified with each app.
How about including a Moiré pattern remover in the JPEG to RAW to remove the print dot effect from scans?
You could have Gigapixel on the main App make your size adjustments then click the next app tab and adjust the JPEG to RAW then tab over to Sharpen then tab over to DeNoise and these could continually speak to each other and understand better what should be sharpened and what is an artifact.
And finally Topaz Adjust, this would make a great workflow staying in one application and saving time and most likely a better result.
I see this as the best way Topaz can get to the next level.
As I said I mostly use Gigapixel, taking the exported image into or from Topaz DeNoise, Sharpen, JPEG to RAW has had numerous unwanted effects and the image gets worse effects.
Please look at bringing together the apps as described above.
I purchased all Apps, and I understand others may not be able to afford this so you could still offer the main Gigapixel then Sharpen, DeNoise etc as additional add ons and simply grey out those tabs.