As discussed previously, this "trick" is actually explicitly not permitted, because you could do something like say "My stock is only work $0.001 each ;)" while simultaneously selling to investors are orders-of-magnitude higher valuations.
I mean, let's be real: the argument in defense of this is that Thiel bought his founders shares at "a fair value". There were 3 original founders, so the argument is that the company had a fair value of.... ~$5k?
> you put in a few thousand dollars worth of them each year before you valuation skyrockets
You can't transfer assets into an IRA like this either.