Best Practices Regarding Syncing Blank Values Between Eloqua & SFDC

I'm looking for some best practice guidelines regarding zeroing out field values.

We have Eloqua integrated with SFDC via the Eloqua Salesforce App. The "Get Contacts", "Get Leads" , and "Get Accounts" imports currently have this box unchecked:

And the Actions for Updating Leads and Contacts have this box unchecked:

This causes problems. We need to be able to zero out fields in SFDC from Eloqua. I'm not immediately thinking of a good example where SFDC would blank out a value and we'd, therefore, need that to update in Eloqua but there probably is such a use case. And we want the field values in the 2 systems to match.