Automate FX chain/FX group selection

I would like to be able to automate or/and realtime play with FX-sets selections.

Let say we have a rhythmic loop playing, several bars long.
We have several FX or several FXSets (Doofers or Splitters).
On this rhythmic loop, I would like to switch from FXSet#x to FXSet#y (in a mutually exclusive fashion) while playing.
Ideally something like a 0-100 master fader, which would behave like:

0 to 24 = all audio through FXSet#1 ; 25 to 49 = all audio through FXSet#2 ; 50 to 74 = all audio through FXSet#3 ; etc. (I hope it was clear).

I tried first a instrument/phrase focused approach (the “Send to FX” selector in Instrument’s FX panel is resembling to my goal), but sadly it is not assignable / automatable (and it’s also sample focused).

Then I tried at track/pattern editor level: by assembling several meta devices and automatic Active/bypass, but I can’t get what I want (and automating active/bypass of devices produces cracks in audio — a bit understandably).

I may now try to use an approach based on automating the “Receiver” of a Send device (to switch the routing of my source track to several return channels/tracks). I guess that formula device may be useful to cap the value (I’m getting “Linked send track does not exist“ message right now).

I think the last approach would work, but it makes the feature quite Song / Song template dependent.

What do you think ? Did I miss a possibility ?

I confirm that piloting the receiver of a Send device with a Formula device works pretty well.

The disadvantage is that it’s a quite hard-wired setup. The Formula + Send combination can’t be saved as a Doofer, and for reusability, you can only resort on “Template song” feature (maybe I should try Quick Template | Tool | Renoise ).

The nice thing is: as it’s purely routing -based, you get the reverb and delay tails when you’re switching away from it.