In the discussion about Opus and AC-3 by @Austin and @Paul2 here, they confirmed that these two audio codecs are the best of the lossy options and are better than AAC even if AAC is more widely supported.
So I suggest that even if they are not as widely supported as AAC, that just for the fact of superior quality that Opus and AC-3 be added as options in the Audio category for export. It also makes sense seeing as how the Record feature currently exports Opus files.
Also, the ALAC preset there is 24-Bit while the FLAC preset is 16-Bit. That’s a bit of an uneven pairing. I think it would make sense to add ALAC 16-Bit and a FLAC 24-Bit presets. And along with that a WAV 24-Bit just to finish covering the bases for the lossless audio options.