Very interesting!
F1 wasn't using air, valve springs, until '86 and still use them today. The 2006 Cosworth CA, a 2.4 liter V8, was able to attain 20,000 rpm with them. Rules have dropped F1 to 18k now.
NASCAR was able to get to about 9,500 rpm with springs and their large valve heads, much smaller valved, 4 valve engines could go 12,000 with springs but, need air, after that.
I'd really like to know more about the PSE system.