Hi virkhausen,
It sounds like Dual routing mode would be the way to go. In the H90 System menu, under Global, set Routing to Dual. This creates two paths – Path 1 uses I/O 1&2 while Path 2 uses I/O 3&4. They behave like two independent mono or stereo effects processors. On a program basis you can put both Eventide presets on Path 1, both on Path 2 or one on each.
For a deeper look into Dual routing mode, I recommend this video: https://youtu.be/0G_WtfUatSc?si=B0ig0phVc3M86VmC
