Back to staff travel for a second.
I take it you realise that in the unlikely event of BASSA winning it's case and staff travel being declared "contractual" for cabin crew, HMRC will be highly likely to tax it as a "benefit in kind".
Given that staff travel means that all seats are theoretically available (ie. including a First Class seat to SYD) and given that all staff are allowed either two additional friends or partner and kids as their nominees, you're lining yourselves up for (another) big tax hit.
If you lose, you don't get your staff travel back so if you intend to continue flying with BA (as a commuter, say), it's going to cost you several hundred extra pounds per month. If you win, the tax man will tax you on the value of the perk and it's going to cost you several hundred extra pounds per month (ironically, whether you use it or not).
Law of unintended consequences anyone?