This very basic setup is a step trigger, switching between 2 Hydras that re-route the trigger to each other. This means each time you hit a key, you switch from one Hydra to the other, calling its specific settings while both Hydras resetting each other’s input to zero. The example switches just pan with each keystroke.
As poor and simple it might look on the first view, it’s a beast and consequent use of this in an extended variation triggered by a keytracking device enables you to setup multiple DSP groups, even cross channel, switchable independent, still saving all your configs with each Hydra (min. 1 Hydra = 1 Config) and to recall whole DSP & FX setups with a single keystroke.
I was just about to reply to your other post and suggest this exact same thing
I haven’t had a need to use a setup like this myself yet, but it did occur to me that something like this would be possible. Discovering new ninja tricks in Renoise is always fun! Nice job.
very nice… thanks for sharing this, Bit_Arts! after reading your other thread this morning, i sat down began to build a device chain to accomplish the task using LFOs. this is much more simple and elegant than the screwy mess i never finished. Cool stuff!
I was thinking about that the other day but couldn’t really come up with a way to do that, your way is a really interesting way to perform that switching, good job.
To be honest, I haven’t ever been in need to switch whole configs. The less with a keystroke. 
But I know for some people it’s pretty common.