The new BA one bag of check-in allowance caught me by surprise leaving Thailand in May. I had a 12 month ticket and flew from Oz to Thailand last September. Sony A1 and EvoPro housing in carry-on, laptop as separate carry on. Maximum bag weight in Oz is 32kgs. I checked in two bags totaling about 36kgs.Nothing said!
Leaving Thailand I've got 32kgs in one bag and 4kgs in another to check in . The BA staff now tell me the rules have changed and I am only allowed one free checked in bag!
Asking price for the 2nd bag is about 130 pounds sterling regardless of weight!
I could fit it all in one bag but then I have a single bag overweight for Australia's 32kg limit.
Eventually we sorted it out as dive gear=sporting goods in the second bag then it could go for free.
This flight was coding sharing with QANTAS if I had a ticket with them, no issue. They don't have a one bag check-in limit; yet.
I was in Bali last September and the camera gear was inspected and a deposit was discussed, to make sure I didn't sell the gear in Bali!?! but ultimately I wasn't asked for any cash.