I learnt the hard way that the ON records do not share a unique identifying number with their fellow records in RE. I pulled a list from ON of some details I know do not sync to RE, I was going to simply do a global add to the records in RE.
It is impossible as the Host ID or User ID in ON match no numbers in their fellow records in RE. The Host ID or User ID in ON SHOULD sync to their records in RE as either the Integration ID or Import ID.
At this point and time there is no way to easily use lists in ON to support data in RE with fields that don't sync, a unique identifying number would give us the same functionality we used to have when using EE to RE!
We have unique ID's for our RE database constituents (PK), which match Core (FK), but can't we use these as a sync field. This is how relational database perform best, with Primary Keys & foreign Keys.! Very frustrating. Give more ability to use various fields to sync.
Wouldn't this be solved by using RE import ID as the host ID in your initial data import into ON?