Tempest Bell area not scaling with knockback effect

In the mechanics description of Tempest Bell, it says it will gain area of effect based on the amount of knockback an attack would have caused. I’ve built into knockback distance on Wind Blast, which already has some sizable knockback, and it does not seem to cause any change in area of effect for Tempest Bell’s shockwaves, visually or otherwise.

Same here, no difference in aoe using wind blast or any other skill using bludgeon support to add knockback.