There now seems to be a noticeable lag when switching blocks on and off within a preset. For instance, I have a fairly simple preset set up in the following manner:
Distortion (Stupor OD) - Wah (Colorful) - Amp (US Deluxe) - IR - Reverb (Spring) - Delay (Transistor Tape),
with the delay and distortion set to individual top row footswitches. Toggling either effect on or off with the footswitch results in a noticeable "hiccup" or delay in the effect engaging or disengaging.