The US-EU "open skies" agreement that allows EU flag airlines to fly to and from EU-US cities specifically says the agreement can't be used to circumvent EU labor law. This clearly, obviously and inescapably circumvents EU labor law, in a massive, flagrant way. Unless you want to claim using Singapore crews under Thailand labor laws (or is it the other way around? lol) doesn't circumvent EU labor law, and then hope you get it in front of an activist court or lawmaker who green lights it anyway because they just want it to happen anyway. Good luck on that I guess.