It can do a pretty impressive job, it does help to use high quality source material. Using mp3 rips from youtube might get a little more artifact-y. sometimes, vocal like instruments will get pulled into the vocal rip instead of the "karaoke" instrument part of the extract.
wait, what's the ATA warning about tinnitracks? On the surface seems like a good idea to me... but couldn't find reference to it good or bad on the ATA site.
Gzip compression benefits taper off in benefit after the "7" setting, IIRC. Brotli at higher settings compresses better, but you'd want to do it static as opposed to on the fly (at higher/highest settings)
Did want to point out some other cheap/free bitcrushers out there for people to try (in addition to MAIM)
https://www.deniseaudio.com/plugins/my-crush is currently free with newsletter sub and was super cheap when I first purchased it.
Some other free vst of note https://bedroomproducersblog.com/2012/03/09/bpb-freeware-stu...
I also like https://camelcrusher.com/