Fidelity Research FR64s Headshell dilemma

I think the key here from Raul is that the P2S mounting distance is specific to the tonearm regardless of alignment choice.  This is what I thought all along.  
So when a knowledgeable person with experience with the FR-64s suggests 231.5 is correct and not 230.0 for P2S, what is this possibly based on?  Actually measuring the EL of his FR-64S arm?  I’m sure someone here remembers what the 231.5 suggestion was actually based upon.  

This is so strange, do you really think that Ikeda, who designed all FR tonearms, and later went on his own with Ikeda tonearms, have no idea about "error" in PS distance ? IKEDA are modern tonearms, designed not in the 70’s like thos old FR. The PS distance is absolutely the same 230mm. In your opinion IKEDA did not realize an "error" in 20 years ?!

I have FR 64s, FR 64fx, Ikeda IT-345
For all of them PS is 230mm, but one designed in the 70s, another in the 80’s or 90’s

Not sure if this is directed at me @chakster but I am trying to figure this out too.  Why is the 231.5 recommended by some when the manufacturer recommends 230?

Not sure if this is directed at me @chakster but I am trying to figure this out too.  Why is the 231.5 recommended by some when the manufacturer recommends 230?

Question for everyone.

It's a conspiracy theory ? 

I just use what Ikeda suggested us to use, i don't care about some gurus. In a conventional headshell cartridge still can be adjusted for any alignment methods without changing PS distance at all. Some headshell have this type of overhand and slots to twist a cartridge body left of right. 

@rauliruegas 
I do understand what you and others have written. My simple question related to the fact that on my alignment guage and as it transpires others that have Lofgren and Bearwald alignments cannot get their cartridge out far enough in the headshell when one mounts the arm at 231.5mm PS distance, whereas at 230mm I can get it aligned. 
The vinyl engine calculator has nothing in it about how far in the headshell you mount the cartridge, nor about how it is twisted in the headhell. That said it was good to learn about the other things that have been written on this thread - which i will no doubt digest and re-read several times