Gimble, thanks so much for your notes. While I had a bit of rare free time today, I ended up making edits of varying scope to the three UESP classic pages at
https://en.uesp.net/wiki/Daggerfall:Enchanting_Items,
https://en.uesp.net/wiki/Daggerfall:Enchantment_Power, and
https://en.uesp.net/wiki/Daggerfall:Magical_Items. From what I can tell (and as my edits to the above pages attempt to explain):
"Cast When Held", "Cast When Strikes", and "Cast When Used" enchantments, whether found on generic magical items or created via the Item Maker service, all degrade with use in classic (? - see below). However, while "Cast When Strikes" and "Cast When Used" enchantments similarly degrade with use in DFU, "Cast When Held" enchantments currently do not. Finally, both in classic and DFU, all remaining magical items holding so-called "passive" miscellaneous enchantments created via the Item Maker service never degrade with use (comprising all listed advantages excluding only the first three - those being when held/when strikes/when used advantages, which are subject to degradation as described above - and all listed disadvantages at
https://en.uesp.net/wiki/Daggerfall:Enchanting_Items).
Some points I'm still not sure about, as also referenced in summary form in the main UESP classic wiki topic at
viewtopic.php?f=8&t=2514, are below. I don't expect you to have all these answers, but I wanted to get this stuff on the page as placeholder items for further exploration by you or anyone else who may have the time and interest:
1)
Is it absolutely confirmed in classic that "Cast When Held", "Cast When Strikes", and "Cast When Used"-type enchantments created via the Item Maker - not merely found as a generic magical item, as I believe was the case with your torc - do in fact degrade with use in classic? In classic, I made a Daedric Helm with the Feet of Notorgo enchantment and unequipped/re-equipped it dozens of times, rested for 7-hour stretches dozens of times, and fast-travelled for 30 days several times, and the helm was still "New". However, this may have to do with the high durability of Daedric armors - see my next point below.
2)
How exactly do "regular" weapon/armor wear and "enchantment health" as currently described at https://en.uesp.net/wiki/Daggerfall:Mag ... ical_Items interact with each other? E.g. does the "12000" value given in the table on that page refer both to the regular combat durability of Daedric weapons and armors as well as to the enchantment durability of such equipment? If so, will a Daedric weapon break if 6000 enchantment points are used and 6000 combat abrasion points are also deducted, or are these completely separate concepts/values? UESP currently has no specific information on how regular combat abrasion/durability loss affects weapons and armors, including weapon and armor durability values for this purpose.
3)
Your testing, as I've also tentatively reflected per my edits at https://en.uesp.net/wiki/Daggerfall:Mag ... ical_Items, indicates 5 points of enchantment degradation each time the item is re-equipped and 7 points per 7-hour rest period, but what are the values associated with the third degradation event, fast travel? Also, are these 5 or 7 points on the same scale as the 1500-point enchantment durability that should be assigned to a torc or other generic enchanted item per the UESP, or if not, what is the scale/total value? Finally, do you have insight into why this UESP page previously indicated "For enchantments that are used as long as the item is equipped, following rule applies: The health decreases by 105 every time the item is equipped plus an additional decrease of 1 for every in-game minute the item is equipped. For example if one equips an item for one in-game hour, it has an overall health decrease of 105 + 60 = 165", which is very different from your 5-7 point sample range?