Gents, I contacted Mark at the Missing Link for advice on connection of several Ref Suppliers wrt direct earth. Here's the reply:
-------------------------
Hi George,
Hope you are well , your own technical earth is highly recommended to get the best performance from the reference supplier.. The key to separate technical earthing is to use one point only so if running 2x suppliers the correct way is to earth the second supplier to the first via the binding posts this way they both share the same spike and keep the impedance to a minimum the 10mm2 is perfect to make your own link lead if you were to add a third Ref Supplier it would again be Earthed to the first ( not the second) .. The other way is to run a separate 10mm2 earth from each supplier to the same external spike... Glad you are using it to best effect look forward to hearing from you soon
--------------------------------

The only downside of this at present is throwing the cable out of the window!

By the way, Mrs Meridian says I have permission to add any number of upgrades I choose as long as they are all at this price! wink

Cheers

George