JJW,
Not sure who you're working for now (sounds like QF, either that or you have some mates who do). Personally 36hrs in LHR is the absolute minimum I need to go to work feeling human. Unlike Emirates, we are either 9 or 11hrs out of our "home" time zone, and sleeping more than 4 or 5 hours straight is a tough ask.
We are at the end of the line when we get to Europe from Australia and therefore need a bit more rest to recover. The comparison to Sing Air or Cathay or Emirates isn't quite the same. When we fly to the West Coast of the US with one sector each way and only 5hrs time difference, then 30 odd hours rest is definitely adequate. Over and back in 4 days is a piece of piss.
As an example, ever done 24hrs southbound in Singapore after operating the QF32 from London (morning arrival into SIN)? Get off the aircraft feeling like ****, can't help but sleep most of the day, up all night and finally getting back to sleep just as the phone rings in the morning to go to work. It's called circadian rhythm and unfortunately there's not a lot you can do about it.
In any case, as long as people like Genex exist to ruin it for everyone then EBAs like this will always get up. I guess if you set your sights low then you'll never be disappointed. Probably why you're not in QF in the first place.
TL