I believe a correct connection profile which includes token retrieval would look something like this, however this "Job Preset" format is not supported by BMC.
"The Job Preset field in the connection profile does not allow for spaces or a mix of literal values and variables, and therefore the authentication field as Automation API requires it ("Bearer $token") cannot be sent. CAR00157536 has been opened to make this possible in a future release or fix pack for Control-M for Web Services, Java and Messaging."
This will be the end of my investigations until a future version of WJM.
Hope this helps someone following the same path!