Based on your preferred features, you seemed to be against coinhive's terms and conditions.
Or you still haven't heard of coinhive's API?

I've seen some ETN pool websites that offers slightly the same features, but I can't remember the link.
There seems to be a performance issues with in-browser mining aside from slower output like the miner stays "Mining" even after hitting stop/pause button. Something simple enough to fix for a good web developer.

This wasn't much of a help but I hope this gave you an hint on where to search.