I'm having trouble with the Smart Chest Content Reader, sometimes it works and sometimes it doesn't - and I don't yet see a pattern to the behavior. Screenshot below.

https://cdn.discordapp.com/attachments/589220170451648515/876211045130182656/2021-08-14-135101_2560x1080_scrot.png

Furthermore, why have a separate entity rather than having the content output in the chest itself, similar to K2 warehouses?

I'm using this modpack: https://mods.factorio.com/mod/Ubiquity_Unstable

I think I figured it out, the Smart Chest Content Reader is direction dependent. It's kind of hard to tell which way it should be rotated but it seems the little circuit prongs on the sprite should be faced away from the smart chest you want to read.

The content reader read the content of the chest which is just behind it (opposite side of the two plot). See the last figure in the gallery. Just turn the reader until the orientation is ok.
I had an external entity because the linked chest provides no intrinsic method to read its content.

Thanks for the clarification.

I noticed there's a limit of 20 different output signals, is it possible to increase that limit? I'm finding that right now my smartchests can become too full and my circuit logic breaks.

I just add a startup setting to increase the limit of output signals

Thanks a lot, it seems to be working great.