I can't tell much difference. Which sharpening method, if any, do you think gives the best results?
The sharpening Topaz applied was default setting, There was no sharpening applied to the noise stack capture. Your observation was the same as mine almost no difference. Reducing noise by using noise stacking has the effect of sharpening also. In this case Topaz wasn't necessary.
PSE 18, On1 Photo RAW 19 & 20, Image Composite Editor, Windows 10