I don't have a Smokey Joe, will it get as hot as a chimney?
I do have a Vortex, if I wasn't so lazy, I could use that under my grate.
I do have GBS, or did (not a fan), but also have that CI sear insert kicking around. I tend to not like the sear marks it makes. I find that ends up being black burned lines where the CI is before the rest of the surface is nicely seared.
I'm a fan of the SnS cold grate technique. Maybe I should just use my Vortex under my SnS grate.