"p.s. these are BA aircraft, so this could possibly be an customer option?"
I think this would be unlikely, Moo. I have access to your manuals by the way, but a fresh set of eyes might spot something.
BTW, had a look at your Wiring Schematics today, but I can't say I found anything to help.
Our flap load relief system will run the TE flaps from 30 to 25 and then to 20 if necessary, but that's about it. No LE stuff.
Regards.
Q.