I use a standard, modern gas stove to do my cast iron cooking and I don't run into too many issues with hot spots in skillets using up to a #9 pan but when cooking for a crowd with my #12 1930's Griswold I obviously have issues with having a centralized hot spot in the pan which is cumbersome, especially when cooking things that want to simmer with the lid on and should not demand a lot of stirring. I am aware of how cast iron is good at conducting heat but not sharing it nicely with the metal around it so we don't need to go down that road. (not that I expect to get a lecture from an aluminum pan evangelist in this forum) I have been looking at ways to "disperse" the heat, possibly with a "diffuser" of some sort although most internet chatter speaks to these "diffusers" being more for induction heating type stoves. One Amazon diffuser description mentions "evenly dispersing heat to avoid hot spots" but then says it "channels the heat to the center opening" which seems counterproductive to me and frankly running the ball to the wrong end of the field. Any suggestions for those of us not lucky enough to have a big fire box stove giving even heat who want to avoid uneven cooking and worse- Warping our treasured ancient cookware?