So what I ended up with (so far) was an Automation.
When a Project [status field] is modified, that record becomes the trigger.
The automation then copies the child table Parts related to the Project into the Snapshot Parts table.
It then copies the Project into the Snapshot Projects table.
It has to occur in this order because I then needed a second automation to create the relationship between the Snapshot Parts child records and the Snapshot Project parent record.
This trigger is the creation of a record in the Snapshot Projects table.
When the Snapshot Parts were created, the related Snapshot Project field was blank. I am currently trying to use the trigger of the creation of a Snapshot Project to fill in the relationship between the two.
If this works, it should be relatively easy to also handle any other child tables that I wish and I am not creating any additional fields.
The potential problem could occur in a multiuser environment if two people change project status at the exact same time. There would be a relationship error. That is rare enough that I think that I will take the risk.
