If you want to use the mix on your board instead of the dry/wet mix on the H9, you could consider using KILLDRY mode, in the system settings, to mute the dry signal when the H9 is bypassed. This will let you avoid phase and volume issues that may come up when you bypass the stompbox is in bypass, and will let you use the mix control as an output volume knob instead of just keeping it set to full wet.
