According to the figure, in the case of the "Legacy lens" in which the red frame is not applied even in the EOS R like the M50,
Even for EF lenses and EF-S lenses, the coverage range is about 80x80% and 99 (11x9) AF points (blue frame) are obtained.
In reports from Japan, it's pointed out that EOS R's automatic detection AF system is almost the same as EOS M50.
EOS M50 using the same DIGIC 8 may also be able to increase Manual AF selectable position by firmware.
List of Red frame and Blue frame in DIGIC 8
https://translate.google.com/#ja/en/https%3A%2F%2Fcweb.canon.jp%2Fe-support%2Ffaq%2Fanswer%2Feosd%2F93909-1.html 