TL;DR
There should be a chest that combines the requester, buffer and provider chest.What ?
I'm asking for a generic logistic chest that mimics and slightly extends what the personal logistic (request / auto-trash) allows but for chests.The chest should allow reading the content alongside it's other functions as this is often required. It should also allow setting requests, provides and trash values either manually or via circuit wires. For the content output and each of the 3 inputs there should be a choice which wire color is to be used. This would allow for example reading the content on the green wire while setting the request on the red wire.
Manually setting values has 3 sliders (values set via circuit logic are ignored). The left slider sets the request value. If fewer items are in the chest then the difference is requested from the logistic network. The middle slider sets the provider value. If more items are in the chest then items are passively provided to the logistic network for pickup. The right slider sets the trash value. If more items are in the chest the excess items are actively provided to the logistic network, they get remove into other storage.
Another feature is the request priority. A chest can request items from other chests that have a lower priority. A chest with low priority acts like a buffer chest with the requester set to use buffer chests. Except now this allows many levels so rings of chests can be placed around the base where each acts as buffer to the outer rings.
A value of X/inf/inf with high priority would make the chest a requester chest, a buffer chest with low priority. A value of 0/0/0 makes the chest a active provider chest. A value of 0/X/inf makes the chest a passive provider chest. Other combinations have even more useful effects.
Given that there is only a red and a green wire not all values can be set independently. But that is life. You can pick different functions of the chest by selecting which colors match. Setting only request and provides via circuit wires and setting the trash value manually or similar should also be an option. This gives the most flexibility.
Construction bots:
I haven't included anything about construction bots in my mockup because I only considered them afterwards. My first thought was that construction bots should always take items out of the chest. But then maybe you don't want that. A simple "Allow construction bost" checkmark would be an option there.
SLightly more complex there could be a pulldown menu to select if construction bots are allowed to take items: Never / Above Requests / Above Provides / Above trash.
There could also be a 4th value for each item to set the construction limit. If more items than the construction limit are in the chest then construction bots can take some out of it. This would also be a better fit to be controllable via circuit logic. But wouldn't fit nicely into the scroll bar for manual input.
Storage chest:
Also not included in the mockup. I think there should be a checkmark "Allow item storage". If enabled then up to the trash value number of items can be stored in the chest. This would finally allow storage chests with multiple filters. Or allow items to be returned to provider chests by construction bots when a ghost is removed.
Note: Not all features used at the same time are mend to be meaningful. For example reading the content on green and setting requests on green will probably set the request to the content + whatever is on the green wire resulting in the value getting larger every time something is added to the chest. This is intentional. Not every combination has to make sense.
Why ?
When the personal request slots and auto trash slots got merged this was a great quality of live improvement. One frequently want's some but not too many items. The same can be said for logistic chests.A circuit controlled requester chest will request items. When the signals change those items still arrive and remain in the chest and might not be of any use anymore. Getting rid of now unneeded items is possible with more circuit logic and active/passive provider chests. But it's a pain to do so every time. Setting the provider/trash limit for the new chest would make this easy.
I also often want logistic chests as buffer between assembler, specifically the belts and inserters come to mind. There should always be some transport belts buffered for the construction bots. Excess belts can be used to build underground belts or fast transport belts. This can be done with a simple wire to the inserter. Construction bots should be allowed to take transport belts out of the chest. But there is no way to prevent construction bots from draining the chest empty. The above construction value would allow setting a minimum number of transport belt left in the chest. That way undergound belts and fast transport belts can still be build parallel to constructing yellow belts. Deconstructing transport belts or removing ghosts should return the belts to the chest so they can be reused to make fast transport belts. This requires the chest to be a storage chest with a filter and limits it to one item per chest. I often put pipes and underground pipes in the same chest. With the new chest both pipes and underground pipes could be returned to the same chest.
The buffer chest is mostly useless in the game. If it is too near to the base then construction bots take forever to take items out of it and they hardly increase the construction speed. If they are too far from the main base then the logistic bots take forever to fill them with items and again their use to speed up construction is nearly zero. It's impossible to set up a sequence of buffer chests that each move items along for a short distance. The new priority setting gives more control over where items are sourced from and allows setting up a chain of resupply depots where each supplies chests with higher priority.
There are probably a million more use cases.
PS: a chests could have more wire terminals allowing for more wires to choose as input / output option. Probably something for a 2x2 chest.