How to change the Input source of Controllers according to the active physical Input ?

[GlennO]

The oldest (and best in my opinion) request related to this problem is, as I said, old, and probably tricky to implement:
Allow Pitch, Envelope, and ADSR receive their input from the input of a grid block instead of a physical jack. Ideas floated have been to specify a block by its row/column, to create a dedicated Detector block, or to assign this capability to a common utility block such as Volume or Filter.

I think that's the crux of the problem. The inputs (sidechain to blocks, inputs to mod sources, and input block sources) probably should not refer to physical inputs. That's too restrictive and it would be better if there was indirection between the jack and the block (or mod source) that responds to it. Allowing an arbitrary block to serve as input seems unnecessarily complicated though.

If the connection between a physical input and an input block could be set by the user (see: https://forum.fractalaudio.com/threads/i-o-routing-matrix.162651/), then all you would need is to select one of the four input blocks as the sidechain input (or input to a mod source).

In other words, set up a preset to use Input 1 Block. Use that block as input for pitch and envelope mod sources and blocks like gates and compressors that use sidechains. You could then freely change the physical input jack or usb channel that is associated with the Input 1 block so that it isn't necessarily connected to jack #1. Your preset would continue to work regardless of where the input is coming from.

Ideally, the looper could be used as the input source as well, but just allowing reconfiguration of the jack or usb channel that feeds an input block would be a big step forward.