I have completed my framework for developing HTML Filters using WebVfx. For a sample of what it can do go to: vimeo.com/257373574. This demonstrates neon-glow text, spinning logos, upward scrolling credits, credits zooming in from the side, stopwatches and gauges.
The framework simplifies creating HTML Overlay Filters. It hides the WebVfx interface and enables you to use a modern browser (with all its development tools - F12) to do the development, rather than using Shotcut, where the simplest of errors creates a blank screen and are extremely difficult to track down.