As part of my compositional work, I create scores that are viewed on tablets using web technologies. The traditional multipage output for print doesn’t fit this use case well and it would be much better for the score to be exported as a single SVG file with all the pages concatenated. Ideally, you’d be able to set the orientation to either portrait or landscape and the pages would be joined vertically or horizontally. While this may seem like quite a niche request, I believe that the increasing use of notation on the web will eventually make this feature worthwhile to many users.
I agree that exporting a multi-page SVG would be useful, but I think possibly a better way of handling it would be to export multiple SVGs but reference them in some kind of HTML container that provides simple next/previous page controls. We might do this at some point in the future.
While easy enough to do, this would only satisfy the standard use case. One of the great advantages of the SVG format is the possibility to manipulate the DOM which offers many other possibilities. In my own work, it is easier and more performant to preload a single SVG file and manipulate the viewbox parameter to reveal different sections of the score. It is possible to export in this way in LilyPond but I would love to be able to work in Dorico. It looks like some great work has gone into producing clean and consistent SVG output.