If you want the H90 connected to both the AxeFX and Kemper my recommendation would be to run the H90 in Dual Routing mode in the Global System Menu. This way, each path on the H90 will operate as an independent stereo effects processor.
Path 1 (I/O 1&2 or I/O 1 for mono)
Path 2 (I/O 3&4 or I/O 3 for mono)
Then you can place both Eventide algorithms on Path 1 in series or parallel, both on Path 2 in series or parallel, or one on each if you want.
Make sure you set the operating level of the H90 based on whether you’re using the inserts for each amp modeler in instrument or line level.
