I actually decided and bought a Line 6 HX One pedal, used. I don't have it yet, but I think it will be the perfect compliment to the AM4, for a few reasons. I did contemplate the cost and going with a more capable FM3 at this point but I dont want the old interface(I have an FM9 already). The HX One is only one effect at a time, but it has advanced midi features so I should be able to send CCs to it on the scene changes to load any effect I want on the fly, unlike another block on the AM4 which is limited to the channels that are part of the block. Also, it has a great Poly Pitch/Capo. It also has great OD/distortions that are at least as good as Fractal (I had a Helix before), so I can stack Drives like I like doing. I can use a dedicated Chorus without sacrificing an AM4 block (Currently using the Delay Trick which sounds good, but I really need that Extra Delay channel to assign delay subdivisions since that parameter is not controllable via a modifier(Which really is needed). Lastly, it has an FX loop that can be assigned by preset, so if I can have it at the input, but then on specific preset effects, like Delay and Reverb) it will run thriugh the Insert loop of the AM4 (only in Mono though).
What I forsee if it all works as planned is a real Input Compressor as an always on effect , unless I need something else, then Drive, Chorus, Pitch as needed, switching per presets or scene. I have to see what I can set up with my Midi controller, but thinking I can also assign Tap Tempo to both the AM4 and the HX One via my midi controller, since the AM4 can't send Midi Clock (Which really needs to be added too). I almost bough an HX Effects which I think would be a perfect companion to the AM4 but didnt want to get too deep, since this is a secondary to my FM9 at this time.