CheerpX is the actual Flash player virtualized. I haven't used it, but would expect that means something regarding reliability. And its customer segment probably doesn't bat an eye at that kind of pricing for something "properly supported", whatever that means for such a hack. Seriously, enterprise environments are often prepared to pay a lot for compatibility stuff/extended support/...

ruffle.rs is a reimplementation, and YMMV, but none of the things I tried playing with it worked properly (although afaik plenty other things do) and still in active development.