The CueTec pin is a true 60* V and yes, everything about it is just that much smaller.
I doubt that a reduced dia. 3/8" std. thread (rod) would work.
Doing so would likely and permanently distort the female threads in the shaft.
There is no doubt in my mind that some enterprising CNC lathe owner could make a run of
these pins and boredom be damned, the machine doesn't care what pin it's cutting.
There just isn't enough demand for a CueTec pin. I've never had to replace one.
Now as Dave suggests, a CueTec drive-mandrel, there is a demand.
I own several manual threading lathes and I can cut a half-way decent thread.
Not good enough that I would consider making pins but I have made a few drive-mandrels.
This may be a good project for some who have threading lathes; cut your own mandrels.
While you've got the lathe set up for threadng, cut yourself a Bludworth and a Cog also.
Or, we could solicit one of our Chinese partners to jump on this but be mindful that
this is exactly how 'job loss' occurs.