Could you help me understand why would you need a client in each framework? It's in vanilla JS and attaches to a Dom element. :)
Edit - one thing to note is 99% of the code is actually just loaded in an iframe. So the actual code on your site is very small.
https://blog.winricklabs.com/(1-25-2020)-making-an-embeddabl...
Edit #2 - no I've only spent a month on this so far.
I would want to see a docs page and a React, Vue, Angular etc client library before I would realistically purchase this and spend time trying to consume it.