"FreeBSD has had 32-bit ABI compatibility for at least a decade"
Longer. I was using linux binary compat, in FreeBSD, to run the linux version of vmware workstation back in 2001.
It has always been very well done, and as you can see, not just running 'cat' or 'echo' linux binaries ... but full blown commercial software packages.
I had Windows XP running, as a dev environment, within the Linux version of vmware workstation, on my freebsd laptop. Worked great.
There was an oft-repeated claim in those days (the days of FreeBSD 4.x) that linux binary compat in FreeBSD would run linux binaries faster than linux would.