There is no option to choose Working or Non-Working Days when creating Transport days per Mode of Delivery - it defaults to Working Days.
This should be an option as otherwise Item Coverage records need to be separately manipulated to choose Non-Working Days but then you lose connection to the Transport Days and won't receive further updates automatically.
We have an Item Coverage record for every Product & Store/Warehouse combination – this is a lot of records to manually manipulate and losing connection to the master Transport Days per Mode of Delivery is not workable.