I was looking at the HX StompXl the Line 6 website......out of curioscity. Noticed an interesting graphic in the picture (below) depicting potential /suggested uses for the HX Stomp.... particularly the 'DSP Expansion' role.. which seemed to show the Stomp as an adjunct to the .... Kemper.*.......... (bottom left)
* Full disclosure, IMHO, having a Kemper coupled to a L6 Stomp/HXFX, or Helix is a GREAT rig - Epic amps and FX in 6u rack spaces.