So far as upgrades to F are concerned , only very senior OAL staff e.g Board Members have any real chance of getting F and this would be arranged in advance between the respective airlines' Interline Departments.
Someone from a OneWorld partner travellling on a Duty Tkt with J priority has a slight chance of getting upgraded
if loads require but this would only happen if there were no eligible BA
staff and is extremely rare.
Occasionally a senior BA
Manager based overseas e.g Sales Manger ,Country Manager or Airport Mgr may auth his counterpart from another carrier to travel F either because he may be useful to BA
in solving probs from time to time or because the BA
Mgr is hoping when he wants to travel his counterpart will reciprocate and offer him an F u/g.
With general ID90,ID75 or ZED tickets there is nil chance that an OAL staff member will get FRCL.
( Remember that the diff between Y and F on BA
LHL is vastly diff then between Coach and F on US domestic...the cost of providng the service is much more...they serve Champagne and Wines up there that cost £150-£200 a bottle ).
The good news is that BA
policy is basically that an aircraft will not depart with empty seats ( barring weight probs) and leave staff behind .They will juggle passengers around between cabins upgrading BA
staff according to entitlement and will upgrade staff 1 cabin above their entitlement if loads require. They will also move Commercials e.g J to F to make room for staff. If flight is open in all cabins you are normally only upgraded according to entitlement unless you work on Check-in when you might get J even if not entitled ...or if you are cabin crew or relative( e.g Wife of optg Capt .) or boyfriend of one of the optg Cabin crew you will probably get upgraded either by the Dispatcher or on the Taxi Out ). On several occasions travelling F , we pushed back with only 3 or 4 in F and by the time we got to the end of the runway there were 7 or 8 in the Cabin !!
Certainly being dressed well helps in being chosen for upgrade but this would normally only become a factor when upgrades are required ......i.e you won-t get upgraded from Y if it isn-t full no matter how you are dressed.
Asking at Check-in or on Board is likely to have an negative affect and some agents will comment you in DCS as 'NSFU' ...Not Suitable For Upgrade ...if you wind them up too much !
In general I have found BA
pretty good . I understand that some carriers such as QF
will leave space availble staff behind rather than upgrade either commercials or other higher priority staff to Premium Cabins to make space avail in Y for the lowest priorities...maybe others can confirm this is so.
Best of luck on yr travels anyway !