If the goods are exported from UAE, the place of supply will be UAE itself and same can be zero rated subject to Article 30 of ER. For the services one may argue that POS is KSA since assembly/installation takes place in KSA based on Article 30(3) of DL but the mentioned Article illustrates a situation where services are done on goods supplied by others. However the services can be zero rated subject to Article 31 of ER. The Implementing State status is not yet effective so it is irrelevant for UAE VAT purposes if the KSA customer is VAT registered or not.