Welcome! This forum has a treasure trove of great info – Scouters helping Scouters! Just a heads up, though - all content, information, and opinions shared on this forum are those of the author, not the BSA.
I suppose the proper way of originally handling my registration as an adult when my son started Scouts was to transfer my ORIGINAL ID to my new council and then register that MID with my new pack. Is that correct? Is there any way to consolidate everything to my original MID and then transfer it from one council to the other?
Original MID - 2165086 - From my Scouting days
New MID - 140265936 - Adult account that was created and has my son attached and adult trainings
No. BSA Member IDs are council-specific. You can put both BSA IDs under management, then set the current one as primary, assuming that the PII all matches (primarily name and DOB, I believe).
There’s a button for Manage Member ID under the left side menu and, I think, under the avatar in the to right corner.
In the event I moved back to the original council, would it pick up the former MID, would some sort of transfer be needed, or would a new MID be created?