Description of problem:
libopusenc 0.2.1 is available.
The version in Fedora is 0.2.
0.2.1 fixes a couple of bugs and I noticed that Fedora has the older version when I was using foobar2000 in Wine to batch transcode some files and noticed that the output on some of them was slightly different.
Presumably the "gapless bug in the LPC filtering" patch is why the newer version in the foobar2000 encoder produced a 1 byte variance occasionally in some of the files I've compared so far, but that's just a guess.
Anyway, the latest version of libopusenc is probably the correct behavior.