Hello, I noticed that the default maximum capacity of a chest is 1000. Is this because an overly large chest will have a serious negative impact on UPS? How big is this impact, and is it essentially the same as the large chests provided by mods like Py? Are these effects related to other factors? Is a 1000-capacity chest that occupies 2 tiles equivalent to a 1000-capacity chest that occupies 20 tiles? If this impact comes from the amount of information during interaction, does it mean that creating a 20,000-capacity super warehouse that is not connected to logistics has almost no impact on performance? And in other cases, do I need to be careful to keep the capacity below 1000 to avoid serious problems?

The performance impact is same as any other chest with large inventory. When inserter is trying to take item out, it has to iterate more inventory slots. Inserters iterate from end of the inventory so having chests which are mostly empty have more impact than full chests.

As far as I know there isn't any impact from just having any size of inventory (except of its impact on save file size). Only inserters (and maybe other entities) interacting with it impacts the performance.

The performance impact scales linearily with number of interacting entities and number of inventory slots the chest has. Chest size itself isn't a factor, just its inventory size.

This mod is all about "setting the limits as low as you can". You can always increase the limits later if you need to, but if you make the inventory smaller later, you will lose items in those slots which were removed.

Thank you so much for the clear explanation! That helps a lot.