The H9 doesn't do this. We call this feature Spillover on the Space and Timefactor (as opposed to DSP+FX bypass which preserves delay trails when going to bypass, which the H9 does do).
We had to leave Spillover out of H9 b/c of the variety of algorithms from the different products it can run. True Spillover requires a second machine running a duplicate of the algorithm that you crossfade to/from when switching presets.
