We would like to use a formula boolean field to synchronize contacts from Salesforce CRM to SFMC.
We know that formula fields are specific and that we should care about its use, because alone it doesn't allow itself any trigger.
Understand How Formula Fields Update with Synchronized Data Sources
Formula fields contained in Synchronized Data Sources update only when an update for another field on the object occurs. Formula fields do not trigger a change to an object or update last modified date fields. When an update occurs, all synchronized formula fields for that object evaluate and update as necessary. Use performant SOQL in those synchronized formula fields to avoid slow synchronization, as these evaluations take place for every field update.
We would like to use a formula field on CONTACT to synchronize contacts from CRM to SFMC.
ALL the fields used in the formula are also on CONTACT (and PersonAccount). So when at least one of the Contact field contained in the formula is modified, and that it updates the formula field, as there is a modification on the record, that should trigger the synchronization. Could you please confirm that in that specific case, we can use this formula field as the field that will filter the Contacts from CRM to synchronize with SFMC ?