Are sub 13lb lightweight flywheels a thing of the past ?

Not seeing any flywheels lighter than 13-14lbs for sale on the market but have seen mentions on forums of them going as light as 8lbs. Tilton had a kit but no longer offers it. What are the lightest flywheels available to us now ?

I’ll be asking the 370z sub as well because I’m on the HR platform but the question stands for DEs as well. Added some clips from a couple YouTube videos showing some revs with a Tilton setup.