I know you jest but...
I can use a cheat instead, would be faster. Or not play in the first place. BTW, the trick with reserve mercenary created only for crafting purposes might not work that well as you think. Crafting only advance during rest - iirc the description of the mod. You'd actually need to drag the guy along. As to ring of mirror images - i doubt that the mod allows to make one. Anyway you can stop yourself from doing it.
On the other hand, does the ability to make items you need and not rely on what you find or ability to make scrolls is a big help in practice or not? There are cost included (like need to use feats). If there is someone who actually played with the mod, please share your opinion.
There is a list of items you can make in the description of the mod:
https://www.nexusmods.com/pathfinderkingmaker/mods/54
It does look like you can make rings or wondrous items with “cast x per day” enchantments.
Anyways, I have been considering the mod mostly for BTSL, since the item selection there is really meager and I’ll often end up with like a +5 pitchfork or something being the only great weapon, compared to the main campaign where they are falling out of the sky. As a case in point, the run before I built my Bloodrager there were two items on the vendor that avoided rage exhaustion. The actual run that I used my Bloodrager, there was nothing. I suppose I could use the Respec feature after I’ve figured out what the vendor actually has, if I wanted to be a purist.
I’m also using COTW, so itemization for the non-base classes is not quite as good. So that might be another incentive.
Re: Mirror image for everyone, not sure how I feel about that. It’s such a huge boost to survivability, but on the other hand, it’s readily available to a number of builds that don’t seem to give up much relative to classes who don’t have it available. I.E., you’re not really making a big sacrifice with a magus archetype over a barbarian and you get mirror image, and this is without any mods. Same with bards and other 2/3 casters.
So if the premise is that locked doors keep honest people honest and you should avoid making mirror image items available by avoiding the mod, well then there is nothing stopping you from running a couple kensai and soloing the game or whatever in vanilla, either. COTW exacerbates the issue, since you can take a Bloodrager, skald, archetypes etc and get mirror.
I think the main issue is that the encounter design is extremely vulnerable to pre-buffing. It would be interesting if they had more frequent dispelling encounters and more prebuffing of their own. Might widen the playing field a bit.
Anyways, tl;dr: Mirror image is too good and I don’t really know what to do about it other than just indulge in it but not going full retard, and I haven’t tried the crafting mod yet but I’m interested in it for next BTSL run.