Doing it post-build is a valid solution for now, but within a production setup it’s quite a quick-fix and pain.
@will Maybe it would be possible to add a flag to set the viewport fit mode within the rendersettings?
An even better solution would be to have an optional index.html which acts as “template”, like the loadings screen. So one can alter the meta tags to add iPhone X Fullscreen functionality, but even embedd small scripts (post-build), e.g. small tracking/analytics scripts.
Just as a suggestion. Have a great day,