I have an answer and will translate:
Not only has the LP12 stiffer springs, but also the old version LP12 has harder rubber bases for the springs.
Consequence:
The Asymmetries of the springs get less compensated and getting those into neutral position again is a pain in the ass. (codeword: Linn-ghost)
Also the subchassis resonance of about 4 Hz is set higher, which makes the choice of carts a harder.
But as with a SME 3009 due it's low inertia-mass only very soft cartridges are recommended, this is less of a problem.
It will be hard to find a soft enough MC cart, though..a VdH Frog would work, but sadly that's in the 1500-2000€ class.
Different tonearms (heavier) like Jelco can also be used, but this can only be handled by a true expert.
I would prefer a high quality MM system with the 3009 myself, classics like Shure, Ortofon with Shibata shape. (500-800€)
*end quote*
So, contrary to my thoughts, he seems to think the Linn springs will not run you into problems in combination with THIS arm.
Personally I would perhaps try if the above mentioned French specialist can offer a set of dedicated 150 springs for you.
The specialist I contacted also mentioned he has a resonance damping baseplate for the TD150 he created himself.
I can provide you with contact data if you drop me a pm.
(I have my phono pre sitting on one of his resonance damping rack boards.
Some of my friends had a good laugh about that until I pulled out the board during play & pushed in the original Phonosophie board instead.
Their laughter died quickly.)
My understanding at the point of info so far is, that you could well go on with MM and a quite better one than your Goldring still with this deck and good success.
Or if you are hard pressed to try MC, then rather get onto a new platform where the arm and resonance situation is fit for todays common MCs from the start.
Either way you choose, I'd keep the TD150, but that is me..
Good luck !