Then what I wrote will not work.
Let us see if I understand correctly:
Project1 and Project2 share the same main datastore
Project2 quartz addon is executing jobs from the main datastore
Project1 quartz addon should not execute from the main datastore but from an additional datastore
It then follows that Project 1 configuration should point to additional datastore, like here
That way Project2 will look into main datastore, and Project1 would “ignore” quartz jobs stored in main datastore and would look for jobs in the additional datastore.