Mint LP Best Protractor

Which is the primary benefit of the MoFi Disk, its designed to emulate a record, only one with the geometry marked right on it.

Actually not a factually correct statement. That it is the ONLY one.
Just one example here for a lot less cash, plenty more on Fleabay.

https://www.ebay.com/itm/Hudson-Hi-Fi-Turntable-Cartridge-Alignment-Protractor-Mat-Single-Sided/254577953444?epid=828455521&hash=item3b46074aa4:g:mJQAAOSwK6Veohh3

The Geo Disc might be better made, nicer to use, that I do not know but I have used the Hudson version for years.

The paper downloads from vinyl engine.

I mentioned using double sided tape and gluing them to cardboard, in order to make it to the semi- correct record thickness. Try to use a thinner cardboard, if you can.

Drill the spindle mount/position hole in stages, so the center point is correct. Do it after it is mounted to the cardboard.

Perfection in the thickness, to some degree, is ’close enough’ as record thickness always varies.

More so, the way the record sits varies even more than the individual record thickness variance itself (or about as much), so the target of matching thickness is a moving one.

Work to get close and learn (via listening and then thinking, in no particular order) to tweak from there.

There is no perfect engineering spec textbook answer that one can rubber stamp their way to a sunshine, flowers and bird tweeting panoramic and perfected dogmatic repetitive eternity...

It’s a use your head and intellectually grow, kinda thing. I realize this might be a challenge, for some... ;)

Those with the kind of cranium that prefers to fit things on the fly, will do just fine here.

Essentially, that: Threads ebb and flow in the clash of these two types.

I have a scout and went through many alignment tools trying to avoid buying this http://www.feickert.org/index.php?id=17&L=1
Go ahead and bite the bullet 
you will never look back
stupid easy and stunning results
have fun Willy-T

I have the Mint LP and GeoDisc. I set up all three of my turntables with the GeoDisc, one was getting more occasional inner groove distortion so I ordered the Mint LP and problem solved.

the bigger problem with the geodisc, IIRC, is finding the center point of the tonearm pivot.

Missing that by a degree or so can and will generally give you a bit more unwanted inner groove distortion.

As we go to (move up the stylus chain of qualities) more and more severe stylus profiles, (Gyger, Fine-line, micro ridge, shibata, etc) this becomes more noticeable.

With conical or the more limp versions of elliptical (0.4x0.7), this can be less noticeable.

So I might use the geodisc, but then do a check on it with the paper protractor. And then see how much the paper says it is off, and then go back to the geodisc and finally see how much I missed the center point of the arm pivot.

A few mm of missing the center/pivot, is a lot, when it comes to inner grove distortion and human sensitivity to such.

this is where the bigger or better and more complex devices show their worth. The ones with an arm on them...to find that center pivot point perfectly, are the better units.

In the end, it tends to be all about inner grove distortion.