Spindle-To-Pivot Distance

@lewm, I think my point is that you can not conserve the effective length of the are because as you increase overhang you shift the force vector clockwise to the point that the stylus can no longer maintain contact with the groove. Buy moving the cartridge back and twisting it clockwise you are turning the arm into an appropriate shorter arm which works at a SPD of 240 mm. I believe it is the only correct approach other than getting an arm that is the right length for the turntable. 
@rauliruegas , what is your opinion on this?

"You believe", is fine.  There really is no "correct" approach, since to begin with there is a built in error that will affect any solution.  Can you further explain what you have in mind as regards the effect of increasing overhang, to shift the "force vectors"?  Are you thinking of the skating force, or what? Of course, you would have to change the headshell offset angle, or twist the cartridge in the headshell, in my "solution", just as for your solution.

Does anyone actually make a decent linear tracking turntable today?

https://www.csport.audio/products/lft1m2-en

livin, if you will get off your motorcycle for a few minutes, you will find that there are several turntables available today that incorporate LT tonearms.  The newest one I know about is the Holbo, which Richard Brand seems to like very much.  There are others, such as one or maybe two models at different price points, made by Brinkmann. There are more, some of them very expensive, some cheaper. (Hope you don’t mind my attempt at humor vis the motorcycle comment.). Other than that, there are also stand alone LT tonearms that can be mounted on conventional TTs. But keep in mind, LT is not a panacea; the concept has its own technical demerits, albeit only a few.