I'd love some help with combinators and setting recipe in a particular case.

[ionic tartan]

I'm trying to create a circuit so that a single crusher switch recipe to reprocess the most present asteroid on a specific belt.
Until now, I've been able to read the belt and set a signal with the recipe I want.
However, my problem is that there are often almost as much carbon and metal asteroids, so the recipe always changes, it flickers. I trying to read the crusher recipe status but don't see how I can make it so that it checks to change recipe only when the crusher completed it's current "build".
Any help appreciated.

[stray hound]

a fairly common problem in the #combinators chat
the main ways to solve it are to latch the recipe (start doing it when 50 metallic above ice/carbonic), or freeze the output signal for a duration (use a selector on randomizer mode for X ticks)

[ionic tartan]

I was thinking of using the randomizer but I'm not sure how. If I have two entry signals, it can be multiple times the same one. Can it emit a signal once?

[stray hound]

it outputs one signal for the duration you set

if you want something to hold a specific signal until it goes away, you can use a latch