Reference the query whether it helps being employed by BA in another position before an internal job offer as a pilot.
A contemperary of mine at a previous company had joined BA as an engineering cadet and then left them to gain flying experience once he got his ATPL.
Several years later he reapplied as a DEP and they did not accept him. Can't think or see why.
Said individual is now a A330 Captain with Emirates.
I am sure he is not losing too much sleep over BA's decision a few years ago.