Firstly thank you for your mod! It's really needed by Factorio!

Replace all these entity/item/recipies with one single "Down Binning chest".
Target quality is determined by the quality of the chest itself.

As for the custom qualities... the following part

local quality_level = {
["normal"] = 0,
["uncommon"] = 1,
["rare"] = 2,
["epic"] = 3,
["legendary"] = 5
}

can be replaced by iterating over "prototypes.quality" and sorting them by "level".
https://lua-api.factorio.com/latest/classes/LuaPrototypes.html
https://lua-api.factorio.com/latest/classes/LuaQualityPrototype.html

I'm thinking about implementing it myself, but I don't think we all really need two mods of mostly the same idea on the mods portal...

Sorry... https://mods.factorio.com/mod/Dequalitier

No problem. I've been focusing on Nuclear Power Rebalance lately so might not have gotten around to it for a while.

But while you're here, would you tell me how you made the graphic? It looks AI but I haven't been following that scene at all.

Yep that's GPT. Well I've done a dozen of promts like "steampunk box top view", but I ended up with "top view steampunk box with 4 blue bulbs 3 green bulbs" etc... Then when I got this variant that is on thumbnail of my mod. With that I went to first site "remove background" and so I got it transparent. And after that I just get steel crate image, without any other hassle I use vanilla shadows, and for image - I just overlay it with generated image, so if you really view it veeery close you'll see that steel chest is still there - under this AI image. All this really took me about 5-10 minutes. For image editing I've used Paint.NET - which is free alternative to Paint, but it still feels like Paint - much simpler than Photoshop or Gimp, and still has layers and transparency, color manipulation - well all I've ever needed for modding Factorio.

I see. Interesting.