The ones in the audio industry/manufacturers have a non-renunciable obligation/responsabilirty with all we customers/audiophiles and this responsability is to give the customer all what he need to operate their audio items.
In the case of tonearms it's just ridiculous that exist " hundreds " of after market protractors because almost no one tonearm manufacturer gives the accurate and user friendly protractor.
The whole responsability is the manufacturer NOT YOU OR ME or any one else.
If the manufacturer can't do it then we customers have to forget that manufacturer and buy the tonearms with the one that has the knowledge level to understand how to build the rigth protractor for his design.
The best busine$$ in audio are not what the audio industry offers but all the after market audio items that exist because the irresponsability of the manufacturers and for audiophiles like you |that are poor demanding about.
For the OP and because what I'm telling here the best option is the MINTLP protractor that is dedicated/custom made for its analog rig and that have all the advantages you name it for a hundred buks.
Well, even those 100.00 should not be a necessity for we audiophiles.
That's happens because we audiophiles have the culprit, we are less and less demanding and other of us have high ignorance levels.
Regards and enjoy the MUSIC NOT DISTORTIONS,
R.