Limit marketo folder / workspace access from Sales Insight (MSI) based on CRM roles/profiles

When starting to use extensively MSI in large organisations, sales will soon start to be able to access far too many Marketo email or smart campaigns. In order to make their life easier and also to reduce the risk of errors (sending the right message to the right person), it would make a lot of sense that, on salesforce side, one could limit access to Marketo folders to certain Salesforce roles. Typical, mid-market sales would only access the marketo midmarket campaign folder, for instance.