Related/alternate idea (recipes output more fluid with quality ingredients): viewtopic.php?f=6&t=120829

This bothered me enough to create a mod: https://mods.factorio.com/mod/fluid-quality-bonus

It could use some optimization and configurability. I'll put some more time into if it gains some traction and/or the base game doesn't adopt this idea.

I was also able to come up with some blacklist solutions. I added some hastily made whiteboard diagrams too.

First, using 3 combinators total, if you only have positive signals:


Constant combinator (CC) with items to exclude set to -1
Arithmetic combinator (AC) with R wire coming from input ...

I wanted to chime in with an additional use case, based around bridging the logistics network to the circuit network:

Multipurpose assembler for low-volume items; e.g. a single assembler to make missing logistics chests, combinators, robots, etc. Right now, I use a constant combinator to set ...