A nice addition would be a combinator which outputs the content of the quantum storage and/or recipe signals of all buildable recipes with the value of how many of this are buildable.

This was actually implemented in a pre-2.0 version of the mod, but after combinators got reworked I couldn't find a way to do it in a way that didn't destroyed performance when hundreds of signals were involved. So I just dropped the feature. If you know a mod that still does a similar thing (outputs hundreds of signals and periodically refreshes them) w/o big performance hit, then let me know, I'll check how it works and maybe reimplement it.

One combinator which could probably deal with dozens of signals is https://mods.factorio.com/mod/Cybersyn-Content-Reader if the content of the train network is very diverse. They solved it to update only every 120 tick by default.

Alright, I dunno what happened, either I did something wrong before, or Wube fixed the performance, whatever. Tried it again, and it works w/o significant slowdown in realistic scenarios.

Added the storage reader. The recipe reader would definitely kill the performance, so I'm not doing that one (and it would be more annoying because of spaghetti)

Hello, I'm looking at your mod, and I'll probably try it out soon.
I don't know if this can help you, but I use this mod occasionally.

https://mods.factorio.com/mod/CircuitHUD-V2

Thanks for the implementation. Works like a charm.