Yes. I’ve been using this htmlviewer as a means of laying out and printing an HTML page. Load up the viewer with some HTML, then in the DocumentComplete event, call the print() method. This has worked OK so far on macOS and Windows, and I’ve avoided Linux as I have a number of issues there, as noted in other threads.
I did wonder why I hadn’t just instantiated an HTMLViewer, rather than having an actual control. Perhaps I did once and experienced then what I found today, that I can do that and use Addhandler to give it a DocumentComplete event handler (in which I then use the print() method), but even under macOS the event never fires (whereas with a real control it does).
Perhaps also @Greg_O_Lone 's comment explains why under Linux, even with a real HTMLViewer (not offscreen but only 1px by 1px and at the bottom layer) print() doesn’t work there either.