The EASA wording does not hang its coat on pilot or operator citizenship (a.k.a. nationality).
They use
[Aircraft] registered in a third country and used by an operator for which any Member State ensures oversight of operations or used into, within or out of the Community by an operator established or residing in the Community; [...] shall comply with this Regulation.
[my bold]
If you, a private pilot, are the owner, then you are probably the "operator" so that bit is probably simple (until you get a defence lawyer involved
).
But yeah.... will your 6 months' stay on EU soil be enough to force you to get the duplicate EASA pilot papers? Nobody knows.
the Aircrew Regulation is not an EU Directive
Does that mean that no EU country needs to implement it?