Our products currently work on raster image layers in RGB images only, in Photoshop. They do not work on CMYK or Greyscale images. They do not work on adjustment layers. They do not work on smart objects or smart layers.
We support host editors in the raster image layer capacity only, and do not see it as a problem, because the vast majority of our customers do not care about smart objects, CMYK, or Greyscale. Instead, they care about which effects they used most recently. We attempt to auto-apply your last used effect, when possible, which conflicts with Smart Object functionality. In essence, we took the path long ago to provide this feature, as requested by our customers, to whom we are beholden.
If you want to edit non-destructively, I would suggest using project files to accomplish that. If we have enough interest from our customers in supporting Smart Objects, then we will do so. Until then, I recommend project files to edit non-destructively.
For what it's worth, I'm not intending to be defensive. I'm only explaining why certain things won't work, if you try them. You can test the statements I've made above, and you'll find them to be true. We support the editors, for what our products are intended to do. After listening to our customers, we've implemented the preferred feature.