good call, as is the case with any spice: a hint is nice, a wallop may be a taste-bud killer.
I'd think about even less than a pound, maybe 8oz, but, like I said, never used the stuff.
Incidently, for example, 12oz of roasted barley makes a huge flavor impact vs 8oz of the stuff, but with other things like crystal 60, the difference is less noticable comparing 8oz to 12oz.
My stand-by rule is to put in less rather than more of experimental spec grains: you can always remake the recipe with more, but you don't have the option of reducing the harshness if you over do it.