This might be far from traditional effects modeling, but I think it would be great if they could implement discreet analog synth modules: Oscillators, LFOs, Filters, VCAs, Envelope generators, noise sources, sequencers, gates, etc. And then be able to use the "voltage" outputs of these things as controllers for other block parameters.
The flexibility of the block ordering, routing, splitting, controller assignment of the Helix seems like it would lend itself pretty nicely creating a virtual patchable analog synth. Plus, most stomp boxes don't allow for external, dynamic control of their parameters. You could add that functionality with the Helix. It would really open things up for some way outside-the-box sound creation.