This is great. A few days ago we were able to enable running Pi fully in the browser (and in the iPhone). Demo here: https://wasmer.sh/?example=pi
I'd be curious if we could compile Rpi to WASIX (https://wasix.org) and get it there as well!
Without a plan of your own for extensions this is comparing apples to oranges. My Pi startup time is dominated by loading extensions and skills, and I don't even have many to begin with!
(It seems like there is a pluging API judging by the Github repo. That wasn't linked in the comments by the time of my writing)