I pained over the Dual vs. Insert options a bit myself, at the start. Dual Routing made a lot of sense in my convoluted setup. I kept trying all the various permutations – noting pros & cons – until I settled on a ‘winner’ (what worked out best for me).
Dual Routing has a lot of advantages, especially since I was matching that alongside similar options in a Poly Effects Beebo. I ended up with Insert Mode, semi-permanently. The Presets in stereo, a choice of in Series, or in Parallel (along with a dry signal that is apparently also in parallel with all of that) allows me to treat the H90 like a mini-mixer.
That conceptualization completely freed up the RJM Mini Line Mixer under the ‘board. I play a lot of synths with the guitars, and the upstream/downstream paths are just as complex. And that Beebo? Stereo inserts to the H90, a mini-mixer in its own right, plus an amazing MIDI generator, living right next-door.
I’m just trying to point out here that the versatility in the H90 lets you take whatever path works out. If you get stuck in the Toolkit conversion process, I can drum up an alternate version. I probably should have from the start, to cover both potential routings. Either way you choose to go, let us know how you made out.