It would be nice to have an overlay for different item categories, to help with organising your chests/storage.

I'd be happy to help with this, I am just opening an issue to see if the idea is feasible.

There could also be overlays for if seeds/fish are in season etc. (or that could be something for the Lookup Anything mod

Hi! Data Layers is only set up for world overlays currently (rather than menu overlays), but I'm happy to discuss the idea if you're interested in contributing a feature for it.

I don't use GitHub issues for suggestions though, so I'll close this ticket. Could you come ping me in #making-mods on the Stardew Valley Discord if you want to discuss further?