I am hoping it is possible to create a formula-driven custom field that can act as such a flag.
Any suggestions appreciated.
12 answers
For that:
-Ceate a process on Account object.
Run it when "record is created or edited"
Add a criteria like this:
[Account].RollupField__c ISCHANGED Boolean True
[Account].RollupField__c Greater than Number 0
Now add an action to update related contacts as shown in image and set the flag to true.
Now create another node criteria, and add criteria like this:
[Account].RollupField__c ISCHANGED Boolean True
[Account].RollupField__c Less than Number 1
Now add an action to update the contact flag to False(similar to what we did in previous action).
