"I will accept that the fragility of a box might require some different attention, but elsewhere this is taken care of by signing a form that absolves the airline of responsibility. NOT having to check it in elsewhere."
I absolutely refuse to sign such forms, unles the Ts&Cs specifically mention an item being checked in. I have had a stand-off a couple of times with check-in agents over skis, but always resolved when somebody with authority in the airline gets involved. I do wonder whether it is often a handling agent trying to trap the pax into absolving the agent.
However, I have no problem taking said skis to the out of gauge baggage belt, which seem to exist in most major euro and US airports, and queing there behind the various cardboard boxes, surf-boards, equipment cases, etc, that go that way.