Employee Commission based on the Role

If we want to give commission to only the "Sales Reps" role on certain product categories, it is not possible. We add roles for bookkeepers, technicians, and managers who don't necessarily get commission, but if they process a sale system record, commission is added against their name as well, which is unnecessary. There should be an option to "Enable/Disable Commission against a User Role" so even if they create invoices, they do not get commission for it.