@Two bags bo***cks
I've run into this "only one bag in the cabin" thing in northern Italy when flying out of Trieste - and they enforce it, you won't be allowed into the plane with two items (handbags exempt if you're female).
But, the Italians have at least got a sensible solution -
i) Check in with two carry-on items, and take a numbered orange tag from the stack at the check-in counter (free, as in no charge).
ii) Pocket boarding pass and wander off for a coffee or whatever.
iii) Attach tag to one item, tear off the counterfoil and stick it in your pocket.
iv) Eventually wander in the general direction of security and get seriously checked over (I've had camera lenses looked through, water bottles opened and contents sniffed etc., even in the days when you were allowed to take water on a plane)
v) In due course drift in the general direction of plane, handing tagged item over to handler at door of plane along with everybody else's extra carry-on.
vi) Enjoy flight (as much as possible, anyway)
vii) At destination accept tagged item back from handler at door of plane - everyone happy - crucial/expensive toys not exposed to vagarities of checked baggage system (ie., not on way to Moscow), but only one carry-on per passenger in the cabin.
This is a very well oiled system that everyone seems to know and use - if it works in Italy why can't it work everywhere else - it's free, but I'd even be happy to pay a nominal fee to use it.
One little quirk - if you're flying Trieste to Munich, one item per passenger, but Munich to Trieste, no-one seems to care.