I'm still new to Helicon. Reading FB posts and forums, I don't see much on the new Render Preview feature. It's great. As I understand, it creates small previews (up to 3240 x 2160) of your images so they can be rendered nearly instantaneously. You can flip through rendering methods, parameter sliders (radius & smoothing), and it even brings out the Autoadjustment parameters to the panel. That was a great idea!
Suggestion: Instead of resizing the input images to smaller previews, why not select a small part of the image at full resolution. That way we could zero in on problematic parts of the image for rendering. (There is no point is zooming in to the preview image downsized to screen pixel resolution.) I think that variant of this tool would be fantastic for comparing the effects of various settings.
Stay safe over there!