There is a House of Commons petition calling on the Government of Canada to retroactively allow self-employed Canadians to use their gross pre-tax income before business expenses when determining their CERB eligibility.

https://petitions.ourcommons.ca/en/Petition/Sign/e-3066

Please sign and share. The petition closes for signatures on January 23, 2021.

More information about the petition and the efforts of the Canadian Federation of Musicians here:
https://cfmusicians.afm.org/news/artist-and-cultural-worker-associations-unions-and-guilds-meet-with-government-to-discuss-cerb-eligibility-issues