I have done the migration yesterday. A useful note: If you use dd to copy eMMC to mSATA, you need to run btrfstune -u /dev/sda1 before any mounting tentative or reboot. Else the system will get confused of the same BTRFS UUID on both partitions and you will be unable to change anything.
An additional note: I did not had any change to do to the /etc/config/wireless file as it was not specifying hardware paths (I am using latest Turris OS 4.0 beta).