It is a cool idea but I prefer to duplicate the layer of the photo I'm working with and then go to Studio for Sharpen. I then take the result back to PSP, and save it with a file name like Studio Sharpen. I'll then flatten the image, duplicate it and go back to Studio for another adjustment etc etc. Why? Well, maybe a distant sheep which looks OK in the original photo looks silly after a Studio adjustment so I can clone it out or alter it with a paint brush before going back for another Studio adjustment. I also like to do opacity and blending in PSP because I can then backtrack and start again from that point if I end up needing more or less opacity etc.
The Introduction To Topaz Studio page says " You’ll get complete freedom to use Topaz Studio as a plugin" Complete freedom doesn't mean using it once then having to close one's photo editor of choice and restart it before Studio can be used as a plugin again.
I'm really annoyed because I purchasecd 5 pro adjustments - Reduce Noise, Color Theme,Sharpen, Focal Blur and DeHaze. If I want to use each of them in succession it means having to exit and reload PSP each time.