Supplier of immovable property may opt to charge VAT on VAT-exempt supply only if the purchaser is VAT registered. Is such a provision compliant with VAT Directive?

Supplier of immovable property may opt to charge VAT on VAT-exempt supply only if the purchaser is VAT registered. Is such a provision compliant with VAT directive?
(ARVI ir ko, C-56/21, opinion, 24.03.2022)
The Advocate General will soon give his opinion on the following questions concerning the Lithuanian VAT legislation:
- The taxpayer (supplier) has the right to opt for VAT taxation of exempt immovable property only if the buyer is registered for VAT at the time of the transaction. Is such regulation compliant with the VAT Directive?
- The taxpayer (supplier) is obliged to adjust the deducted input VAT borne on the acquisition of the property if the buyer is not registered for VAT at the time of further supply. Is such practice compliant with the VAT Directive?
- The buyer filed the registration declaration one month before the supply and was registered one month after the supply. Are these circumstances relevant to the answer to these questions?