I’ve been watching videos, reading blogs and the forum (even writing the odd message), examining the plugin store and pedalboards, trying to work out which bits of kit I have that will connect to it (Korg NanoKontrol 2 possible? - I reckon so) reading the wiki and my expectations are sky high at the moment - am I expecting too much when my Dwarf arrives and will I be disappointed, or will it be as wonderful as I think it’ll be?
Just asking 
I also dated my Duo X for months ahead of purchasing. So I can relate. 
Most certainly. One of the most praised features in all of the videos I watched before – and you might have watched the same! – is that controllers are recognized instantly. It was certainly the case with my Akai APC Mini. Now, as far as passing midi signals through the MOD into your computer or other hardware, I have yet to test that. Other members may please comment here.
Are your controllers MIDI?
Then they will work.
What will not work is controllers that are HID (Human Input Device) and there are quite a lot of those out there (some can do both), but the vast majority is most likely MIDI.
If I understood correctly what you want to achieve here, you just need to plug the input of the desired controller directly into a MIDI out on the WebGUI. It’s that simple