Multiple sites - no multisite

Hi,

We’re looking to set up a construction of 50+ sites with one WP install, no multisite.

Can anyone share share some thoughts or insights how/why this should or should not work?

I believe this should be possible if the WP REST API endpoints are customized.
As i see it we can provide data depending request URL of extra parameter when requesting data through REST.
So if site is website1.com we return data relevant for that site.
If site is website7.fr we return data relevant for that site etc…