Restrict Smartview submissions via Ad-hoc spreadsheets in PBCS

The client would like to restrict the users' ability to submit data via ad-hoc reports/spreadsheets as it would potentially create data inconsistencies since the business rules are triggered on save. We understand that a way to prevent this is by having a business rule to recalculate everything either throughout the forecast cycle or at the very end. But assuming that is not feasible short term, is there a way/role that would allow the users submit via the forms but not via ad-hoc reports?