FreshTomato is still active, and they are doing x86 builds now. I'm running it on an aging Netgear R7000 and it has been stable.

I used OPNSense briefly when I got 1gig synchronous fiber ~2015 at home on an old i5 desktop, which I think was shortly after the pfSense fork, and then found Mikrotik and RouterOS. Used RouterOS at home since and have been replacing aged out Cisco switches in the datacenter (100gig) and closets (20-40gig) cheaply. I'm looking to dump a handful of ASA's for OPNSense and the messing around I've done so far has been positive. It's aged nicely.