It is, but only with developer hooks. I don’t really provide support for the developer hooks here, but there is documentation about how you might do this specific thing. See this page.
I have a question about the hook you referred to, Jonathan. Do the fields have to be in the fieldmap for the conditionals to work? I will need to use this functionality. However, I don’t necessarily need to store that information. Just need to check it to see if the given record should be imported.
@blipps good question. You could try it and see, but I think by default it probably would need to be in the fieldmap because $object is the result of a Salesforce API call that uses the fields in the fieldmap.
If that’s correct, I think if you wanted to, you could use object_sync_for_salesforce_pull_query_modify to modify the query and add those other fields in to the resultset, and then use object_sync_for_salesforce_pull_object_allowed to work with those fields. I’d test it a lot, but it is probably possible.