SFDC/MSI sync error

I have a situation where interesting moments have been created in the past in Marketo, but MSI is not installed in SFDC, so everytime MKTO tries to sync a record that has an interesting moment with SFDC, there is a sync error because the field does not exist in SFDC.
The error is
INVALID_FIELD: No such column 'mkto_si__Last_Interesting_Moment_Date__c' on entity 'Lead'. 

The SFDC group is very hesitant to install the MSI package so that is not really an option to solve this issue.  
My question is, what are my options to stop the sync errors from happening.

• Is it possible to clear interesting moment fields in MKTO? (I do not think so)
• If I have Marketo remove the sales insight package from Marketo, will it remove the associated fields from the lead DB, or will they stay behind
• If I have the SFDC group create those fields manually in SFDC without installing the MSI package, will that potentially solve the problem?

Any help or insight would be appreciated.

Thanks,
Jason