Basicly, it is still not possible for Canadian users to use Zoho CRM app in make. There was a previous issue raised concerning this topic (Zoho CRM needs Canada Datacenter).
It has been flaged as fixed even tho the solution OP was presenting was a very annoying patch. It works well and OP did a great job finding a work around, but it still is not a solution to this problem. Also, the solution has other issues such as refresh tokens not refreshing with the http oauth2 app, wich makes me and clients forced to re-validate the connection every hour (not the best for automations…)
There absolutely should have .ca added to the domain list in the Zoho CRM app.