At what point would you step up to ferrea hollow stem valves

Yeah. Remember when they used hollow exhaust valves in medium and heavy duty trucks filled with sodium to keep them cool? Did it for a LONG time. Probably from the 40s to the 90s I bet. They finally quit. You know why? You know what happens when pure sodium hit any moisture at all? It explodes. Violently. The valve stems were cracking and exposing the sodium to the moisture in the exhaust and bam. They finally stopped that stupid crap. I don't care who makes um, or who runs um. I wouldn't trust a hollow stem. While the performance versions are certainly not sodium filled, use your imagination and think about how thin a 3/8" valve has to be that's hollow. I just wouldn't do it. I'd look for other areas to save weight. Just my opinion.
FYI trickflow is 11/32. Loosing weight on the car is going to be the task for this fall. My goal is 10.00-10.20 area so maybe I won't have to spin it up real high & since I'm the head bench guy at work I can always do stuff like titanium retainers 1st & add later