Andyr's caution may or may apply. If, for example, you have a swivelling armboard as on a Teres or Galibier, effective length is a non-issue. What table are we talking about anyway? Supplying complete info would get you better answers. :-)
At any rate, if your Graham-drilled armboard swivels to adjust for effective length, then a TriPlanar can be mounted it. The TriPlanar's three mounting holes fall outside the diameter of the center hole used by Graham, Rega, etc. You'd just have to drill and tap the holes.
I don't know about Linn or VPI, though I'd "guess" a JMW-10 or above is similar to a TriPlanar in how it mounts.
At any rate, if your Graham-drilled armboard swivels to adjust for effective length, then a TriPlanar can be mounted it. The TriPlanar's three mounting holes fall outside the diameter of the center hole used by Graham, Rega, etc. You'd just have to drill and tap the holes.
I don't know about Linn or VPI, though I'd "guess" a JMW-10 or above is similar to a TriPlanar in how it mounts.