Thanks for replies guys.
If anyone's interested, after a few days of research it seems it's now completely impossible to do in Asia. There's one UKCAA approved sim left out here, at HAITE in Singapore, but they don't have a UK ATO or any UK examiners on their books so they can't help us. The ones in BKK are no longer approved. Basically nobody's bothering to pay the CAA inspection fee any more since Brexit.
Off to Gatwick I go
