I don’t see how design workflows matter in the conversation about cross-platform vs native and RAM efficiency since designers can always write their mockups in HTML/CSS/JS in isolation whenever they like and with any tool of their choice. You could even use purely GUI-based approaches like Figma or Sketch or any photo/vector editor, just tapping buttons and not writing a single line of web frontend code.
It's bad enough having to run one boated browser, now we have to run multiples?
This is not the right path.