With 2.91 on the HX Stomp you can no longer use the "Simple Pitch" or "Whammy Pitch" to "downtune" your guitar, because the signal of the original guitar will be added to the mix, no matter the mix value is set to 100%. I think this is a bug, because I used this feature a lot to play along tracks with Eb-tuning, while leaving my guitar at standard tuning.