Hello orogor:
Many thanks for coming back to me with such a lot of information - much appreciated. I’ll bypass some of the comments considering uroni’s reply, but here is some further response which others might find useful:
According to Mac OS 10.13 HighSierra (APFS?) client fails - Sierra works - #18 by Falko_Trojahn this is now resolved with client 2.1.17.
I am using BTRFS - but on a Synology NAS; this seems to have quite an old kernel, so is failing the BTRFS detection test.
Ok - that’s great to know. I will investigate.
Thanks uroni - I’ll look into that. Many thanks for such a fine utility!
Best wishes,
Pants.