Dihaz
I can imagine that time to command on the 747/777 is long but what about on a small fleet like the A380 where perhaps not all the existing FOs have the relevant experience for upgrade...
The current projected numbers from the internal bid show the 380 as being rather popular. Since BA still allows internal transfers I'm afraid fleet size and the experience of F/Os currently on the fleet doesn't really enter into time to command.
Most of those currently going into the LHS of the 380 will be captains moving from short haul, the rest will be off other Long Haul fleets (Captains and senior SFOs). I can't see that changing any time soon so I really don't think joining BA on the 380 with bags of experience is going to give a fast track to command.