I've migrated Thunderbird across many Mac OS's and hw systems by just copying the default profile to another machine then editing installs.ini and profiles.ini appropriately. This successfully migrated everything - gigabytes of mail, extensions settings etc. - all worked fine - but the machines were all Intel Macs. Now I want to do the same trick to migrate to a Mac M1. Something tells me it won't work because the extensions will be for an Intel architecture. How can I do this ? Thanks Andy Heath