Does the D-Two effect spill-over during patch changes? Or is it possible to allow the delay to ring out in another way?
Unfortunately, the D-Two does not include spillover at preset change.
During preset changes the delay time is updated to the new preset parameter setting instantly, killing the previous setting. But it is possible to let the delay "ring out" when bypassing the D-Two. That requires the "Bypass" parameter to be set to the "Fx In" setting, which are set in the "Utility" menu.