Let's ignore for a second how silly 512k lossy is for a moment. Is there anything Q10 Vorbis or Q10 musepack do that WV hybrid can do fine. Because I'm kinda confused why Vorbis can do 500kbps for stereo audio, or was just leftovers from when <480k 5.1 audio was a thing?.
MUsepack Q10 is actually around 4:1 compression for cd audio, While vorbis q10 is around 3:1
Vorbis q10 should give 1000k for 5.1 . I guess Q10 is there as a proof of concept for overcoding / transcoding etc.
For musepack, levels higher than Q7 insane were added with a quality scale for 0 .. 10. anything higher than Q6 xtreme
was generally implemented for similar proof of concepts .
I think 512 isnt so crazy as its the mid way point (560k) between 320k aac / mp3 and 800k lossless.
Its still significant ( up to half of lossless) compression in most cases. Not that mpc / vorbis actually need it.
Lossy codecs are usually made with some strong assumptions about what losses are acceptable (not necessarily intentional, some can come from bugs or design choices which make some stuff disproportionally difficult to handle)
for these codecs, there is a point when it doesn't make sense to ask it to use more bits, because it won't meaningfully improve audio quality; problematic samples which were not transparent will very likely continue being not transparent, because the "level of destruction" doesn't scale all the way back to "none"(lossless) but instead stalls somewhere.
Lossy codecs are usually made with some strong assumptions about what losses are acceptable (not necessarily intentional, some can come from bugs or design choices which make some stuff disproportionally difficult to handle)
for these codecs, there is a point when it doesn't make sense to ask it to use more bits, because it won't meaningfully improve audio quality; problematic samples which were not transparent will very likely continue being not transparent, because the "level of destruction" doesn't scale all the way back to "none"(lossless) but instead stalls somewhere.
I've had MPC use up to 850kbps at --standard on some prurient albums, Where on other codecs it 200 ~ 384kbps. Almost like Musepack gives up trying to stay at or under 320k, Just pretends it lossless codec on its high setting on hard electronic samples with noise mixed in.