Forgive me if I'm missing something, but I don't understand the need of washers, and what you are trying to accomplish with them? VTA adjustment, or Azimuth? Isn't there other ways to fine tune such with your tonearm?
I'd assume disconnecting the cartridge "after" your hard earned work of alignment will be definitely counter productive.
Macdad, Yes, it is a bugger, and I'd assume cartridges like the Dyna Karat, with it's ultra short cantilever are a real "joy" to align.
Hopefully, you also ordered the 10X "Lupe" as they call it, with the Mint Protractor, I did find this tool quite useful, as its plastic housing is removeable, thus letting you get closer to the stylus. This is the hard part, you must have the steadiness, and precision of a micro-surgeon, and due to the short depth of field, getting close can be hazardous, in that you'll bump the cartridge flying across the protractor-platter.
You definitely need good lighting that you can easily position at various angles, this will be a tremendous aid. I found my Littlite, with 18" flexible Gooseneck indispensible for such use.
I found the kitchen table a good work surface, in that while sitting, I was right at the comfortable level I needed to be, to get right down there at the Stylus-Protractor interface. Comfort will also be paramount, because you will be doing this alignment for a good length of time.
After close overhang adjustment, one then must align the cantilever, and this is where the MintLP device really shines, but while doing those minute adjustments of zenith angle of the cantilever, one can again lose correct overhang. One key is the exact, precise preliminary tightening of the Cartridge Body to headshell, so that you can make these very minor adjustments, without continuing to lose them.
I did also find the small lit magnifier that Yip sells to be an aid as well, but if you didn't order such from him, one can commonly find these at Wally World for about $4-$5.
The more optical, and lighting aids you have, all the better. Hope this helps. Mark