I repeat - normally MIDPOINT IS ACCEPTABLE.
NOT in the opposite direction, it isn't.
Look on the approach chart, the minima will be specified for the particular runway in use.
IF no RVR for the landing runway is available...no other RVR for another runway is acceptable.
BOAC I can understand...he always seems to have an oddball obtuse opinion.
IE: to be expected..
For others...read your individual airline's Ops Specs....as therein will tell the tale.
NB.
And this brings me to another scenario...IE: those pilots who are too darned lazy to actually
read and understand their airlines individual operations specifications, provided by their respective carrier....and come to some rational conclusion.
IE: those that contribute to PPRuNE on the tech forum might have no idea about those ops specs, so...can only provide general guideance.
IE: specific questions require specific details about the concerned regulatory authority....as without same, only general guideance can be obtained.