Hi guys,
Just to clarify, there's two locakout switches for the EAS on Range Rover Classics, that do different things.
The lockout switch on the dash, between the up and down arrow switches, basically stops the suspension lowering at 52mph, e.g. when towing. Press this and it won't go down and neither will it go into raised mode if you push the up arrow. However, the EAS still works on all other regards, i.e. will self-level and if it does sink overnight, will still raise to standard height. So all this does is keeps it in standard mode.
The lockout switch under the seat locks the suspension wherever it is set. So if you have it in access mode and flick the switch under the seat, that's where it stays - e.g. if you're in a low clearance car park. Equally, if your in raised mode it'll lock it there too I believe - although I wouldn't recommend it as it won't lower at 35mph and is pretty unstable then!
That's my understanding anyway, HTH.