Thanks Sam, thats encouraging.
However, I doubt its the most “Elegant” path forward, having to have two additional drives semi permanently hanging off my lap top, particularly if I want to make use of playlists and iCloud photo options on my iPhone.
I must say, I find it disappointing that in order to properly replace my ageing 3TB 27” iMac I now have to buy TWO expensive pieces of kit, the Studio display and an “M” architecture based machine, and that to do this with a similar amount of built in storage, (4TB.) is in my view cost prohibitive, (Don’t even get me started on the extra £400 needed for the hight adjustable screen option!)
Thanks again for the feedback, much appreciated,
Steve.
They should be fine as long as you format as macOS Extended (Journaled). APFS performance on spinning disk drives is abysmal.