I also use Topaz Studio 2 as a smart filter from Photoshop. It would be really nice if Studio 2 saved its state, so that the next time I open it from the same Photoshop document, all the settings are unchanged, even if I quit Photoshop and then re-open the Photoshop document.
For example, I run Topaz Studio 2 as a smart filter, add AI Clear, set opacity to 0.50, and click Accept. Back in Photoshop I double-click the Topaz Studio 2 smart filter. When Studio 2 opens, I want to see AI Clear open with opacity still set to to 0.50, but it actually looks like Studio 2 is being opened for the first time.
I know it is possible for Photoshop plugins to save their states because Skylum Luminar and Nik Silver Efex Pro 2 do so when used as Photoshop smart filters.