Travel / Polish citizen with expired Polish passport, flying to Poland on British passport via NL [2]

Background: My wife and daughter are both Polish citizens but have expired Polish passports.Getting an appointment at the London consulate is a nightmare. They do both have valid British passports.

Situation: We would like to visit my wife's parents in Poland, and renew their passports once we arrive.

We are thinking of flying via Amsterdam so we clear the border in NL on British passports and avoid the inevitable questions at the Polish border around Polish citizenship etc.

Question 1: Will we encounter any passport checks on the NL -> PL leg? I would think not, since Schengen?

Question 2: Will we encounter any difficulties on the return leg from PL -> NL? Will my wife be challenged for presenting a British passport to the Wizzair check-in agent?

My wife is concerned about needing a Polish passport even to fly within the Schengen zone. I think we can get around this via the above method but I'm wondering if anyone else has done it.

And yes, the situation at the Polish consulate in London is THAT BAD that we would prefer to do it this way if possible.

Thank you / Dziękuję