So, one of the things mentioned in Core is that the Order no longer permits the sale of enchanted items to mundanes that do not have some form of expiry built in (p 16). The errata state that the expiry rules in the Core rulebook only apply to invested items. This effectively means that you cannot sell lesser enchanted items to mundanes, unless you restrict the users, which comes with its own set of disadvantages. Does it seem reasonable to allow lesser enchanted items to be made with an expiry, but without the expiry providing a bonus? It seems to me this might reasonably fall under the heading of an environmental trigger condition, though one that might have to be combined with an active trigger?
ArM5 p.16 mentions, that charged items may also be sold to those not associated with the Order. AFAICS these would be the typical minor magic items for sale to mundanes anyway.
A magus wishing to sell more powerful enchanted items - also permanent ones - to mundanes can always use the services of a Venditor (ArM5 p.16, HoH:MC p.136).
Cheers
Because of the mechanics of Effect Expiry this option does not make sense for Lesser Devices so this is indeed a pickle. IMHO the Errata should have included a "time limit" option for Lesser Devices which has no benefit for the enchanter but makes sure the device stops working at some set time after being taken into use. Looking at the Effect Expiry this could be 70 years, a shorter period seems too harsh. Otherwise
My take for several years has been that effect expiry was too powerful and it made the game less fun so I'm in favor of it not providing any bonus whatsoever even on invested devices. But don't let my grumpiness deter you. I think that allowing expiry with no benefit on lesser devices is a fine house rule. I see no contradictions or problems with it.
... d*mn Erik, you stole my line.
Note that "some form of expiry" need not refer to the expiry rules in the Core Book, which are really meant as a "flaw-in-return-for-a-bonus" thing. There are several ways one can build "some form of expiry" into a Lesser Enchanted Item.
The least effective is probably to cast some form of a Watching Ward ritual on the item, set to destroy the physical form of the item (no need to disenchant it) after a set amount of time or when a specific condition presents itself.
Another option is to keep a sufficiently long-lasting arcane connection to the Enchanted Item around, with a note about the need to switch it for a mundane version of it after a set amount of time or when a specific condition presents itself. Ideally, the mundane version carries some obvious cosmetic changes (say, an enchanted copper ring gets switched for a broken and tarnished copy of it) and the mundane buyer is explicitly told that those will be the symptoms that the item has "spent its power". No need to inform him about the switcheroo, really. This has the huge advantage that one can resell the item over and over and over 
Yet another option is to create the item with a trigger that, instead of being , is AND . E.g. a magic sword with a trigger that, instead of being is <when touching flesh, as long as some time in the last thirty years the blade has been held aloft at least three hundred paces above the ground, while invisible, with the word "gobbledigook" being uttered thrice in its presence>. Remember that triggers can be arbitrarily complex. Similar to the above, the "spent" item if recovered can be easily "re-enchanted" and resold!
We've probably read many of the same posts.
Probably 
Back in 4th ed we used the Wizard's Grimoire, revised with the additional rules for lab specialities. While I like 5th ed lab rules much better 4th ed had a "Speed" speciality. It was added to lab totals for when you already had high enough total to eventually finish the project. For with a lab total of 51 for a level 50 spell you would take 50 seasons to complete it. But with a +3 lab you exceed spell level by 4 so the project could be completed in 13 seasons instead.
IMHO this is kind of what Effect Expiry does - allows you to finish an Invested Device faster, or to make more powerful devices in the same amount of time - but at a sacrifice. But it is waaaay to powerful, the modifiers to the excess is too much.