I'm currently using a Behringer 173 module as what I would call a "gated effects send", which is working fine but it uses a lot of patch cables and requires using a mixer module for each audio signal. The basic idea: I have an incoming audio signal and gate. When the gate is low the original audio signal is returned, but when the gate is high the audio goes through some processing.
Rack here:
I'm currently using this with a sequencer to send a drum gate, and that causes the kick and bass to be passed through HPFs. I make a lot of trance so this is a useful way of transitioning between sections. But there are other uses too, such as using big delays to emphasis one or two notes in a sequence without muddying everything.
My ideal module would be something simpler that uses fewer patch cables and less space. It might also be nice to be able to blend between the signals instead of using the gate to switch between wet/dry. I found a DIY option, but I'm hoping there are other ready made alternatives.