Update on teething issues discovered:
Ensure that the laces lay flat on your skin especially where you tie off or you may loose skin.
Another area to watch is between your toes with the 10mm leather lace that comes as standard on the Luna.
One sandal had the lace cut back to say 6-7mm where the leather passes between the toes and I had no problem I lost some skin until I cut back the other sandals leather lace.
Getting the tension on the heel strap takes experimentation especially if you have injuries that cause one leg to be dominant.
With the weather getting colder here I found the need to over tighten before leaving the house as your feet will contract until well warmed up after 20 minutes when the leather comes into its own and creates a snug fit
A few small blisters in new places initially no recurrence once adapted to the new footwear, most likely due to my asymmetrical gait.
Insulation from the ground is good with air temperature close to freezing, toe socks will be used if it gets much colder.