Problem with this is similar to Channel Islands with Jersey, Isle of Man etc. that still majority of the Banks don't use SEPA Transfers - for Example in Channel Islands I'm only aware of Barclays International having SEPA Payments while Standard Bank International, Santander Bank International and non of the smaller Banks use SEPA at all.
While you have then Jurisdiction every Bank has SEPA access like in the UK and Monaco.
Yes, Serbia Banks are not the best to work with - back then Serbian Clients claimed weeks of Processing Time for SWIFT EUR Payments from UAE to Serbia.