Hi Adam,
The H9 has a Pre/Post capability that allows you to use I/O 1 for PRE and I/O 2 for POST. If you connect your amp’s FX loop to I/O 1 and connect your HX Stomp’s FX Loop to I/O 2 you’ll be able to switch which amp/cab setup your affecting by choosing PRE or POST in the algorithms Menu on the H9. In order switch between the two routing mode, you need to use the H9 Control app.
The H90 makes it easier. It has a Dual routing mode that makes the H90 behave like to independant mono or stereo effects processors. So Path 1 could be connected to your amp’s FX loop, while Path 2 could be connected to the HX Stomp. You can have one playlist for amp FX and another playlist for HX Stomp effects. Switching between them can be done on the pedal or the H90 Control app.
