https://mods.factorio.com/mod/verysmallchests
Is it possible at all to add support for this mod? Thanks.

It might be possible but I don't plan to add support for chests from this mod.

OK no worries. Do you mean that this is the wrong mod to be asking, or you will not be adding any more types of chests? The chests themselves are just clones of vanilla chests with 1 slot of storage. I thought they would be ideal to merge to save UPS, for use on Space Exploration recipes and for use as UPS cheap belt balancers.

As you said, the are not new types of chests so I didn't think it was necessary. You can set the inventory size limit on individual chests.

So only benefit would be the UPS savings but AFAIK moving items to chests is not UPS heavy. If you have a base where performance is a problem you can test it by modifying MergingChests's mod "Inventory size limit" setting to 1 and check if it improved the performance.

Just be sure to not to save or at least not use any autosave. Change the mod setting back to previous value before continuing playing you save.

I see what you mean now. Thanks for that, I'll give it a try.