In know that if I buy duty free liquids in one EU airport, and have them sealed in the special security bags with the receipt shown, I can take them through security at other EU airports the same day. Details on Europa.eu. (With the proviso that they'll probably be subject to additional screenings or inspection, and may be removed from their bags then re-sealed again in a new one, which will take extra time)
On an upcoming journey, I'll be flying from outside the EU into one EU airport, then connecting onto a different EU airport which is my final destination. For the intra-EU leg, I won't be able to buy the cheaper "real" duty free, as I'll have arrived in the EU customs area by that point.
Given that, if I want to buy something, the place would be at my non-EU departure airport. However, I'll be transiting on the way, and having to re-clear security.
What are the rules on non-EU purchased duty free in security sealed bags, going through transfer security at an EU airport? Is it treated the same as EU purchased duty free? Is it always allowed? Only allowed from certain origin airports?
(I've found this Europa.eu page from 2013 which lists some allowed non-EU countries, but also says that changes are coming, and it's 2 years later! This other Europa.eu page covers departures from EU airports, but not my case, and I couldn't spot any others.)