In Finland you can declare DHL/UPS/Fedex packages yourself with customs and pay directly to them, with no fees to carrier (it took a Finnish Competition and Consumer Authority decision in 2017 to get rid of the fees, though). But this is a bit different as it is not a hidden option but standard procedure (though you still get the option of paying the carrier to declare, instead).
Declaring inbound packages to Customs by yourself was already the standard here for postal parcels even before Customs internet services, so this was not a completely new way of working.
