here is Ferrea's Super Flo vs. Flo valves:
notice that the Super Flo valve is what we call "under cut".
the stem is tupiped and made smaller/narrower to allow more air volume to stack at the back face of the valve before the valve opens and carries more flow volume as the valve opens down the "curtain area". The Supertech valves are also undercut and tuliped.
in most cases, high heat and high cylinder pressure applications tend not to have this "undercut" since it may weaken the stem with those extreme conditions. But Ferrea is able to undercut their intake FI stainless valves.
You'll have to see what the limits of those Super Flo valves are in FI applications. You may end up getting the Flo style instead depending on your priorities.
Here is a set of turbo application dished Manley stainless valves for the Honda VTEC Bseries:
notice that they are not undercut but instead have a beefy stem and have a dished face.
Most N/A motors tend to go for the undercut whereas the FI people prefer strength.
here are Supertech valves that have not been "undercut":
Dished valve faces add chamber volume and therefore reduce static CR whereas flat faced valves increase CR by reducing the head's chamber volume.
Notice the back of the valveface is not mirror smooth. Again smooth surfaces generate flow "stickiness" and create unwanted turbulence.