TL;DR
Instead of setting requester chests to take from buffer chests, set buffer chests to provide for the logistic network.What ?
Remove the checkmark "request from buffer chests" from requester chest.Add checkmark "provide for logistic network" to buffer chest
The checkmark sets if the contents of the buffer chest are only restricted to the player logistic request and construction bot request or available to the whole logistic network (rather than wether the logistic chest can request items from (any) buffer chests or not).
Kinda like this:
Why ?
It is necessary to decide wether buffer chests should send items to requester chests or not (See FFF-222, the origin of the checkmark)It is much more logical to decide for each buffer chest to provide to all requester chests rather than decide for each requester chest to request from all buffer chests.
This solution solves the problem in the mentioned FFF better because a different requester chest which needs to request from some other buffer chest could still pull from that chest.
Another way to look at it: This way you can have "In out" buffer chests for upgrading stuff or as sorted logistic storage and "shortcut" buffer chests at the perimeter where only construction bots should draw from.
I know it's a tiny thing and a bit late in the development, but something I struggled a bit with when it was introduced, because it didnt quite make sense to me, as the logic there is kinda backwards.
Side effects:
This could allow "elevated" buffer chests to send to other "normal" buffer chests, especially if you take that wording I used in the picture literally. "Elevated" buffer chests shouldn't provide to other "elevated" buffer chests though, similar to how they work currently.
Read material:
Buffer chest introduction: https://www.factorio.com/blog/post/fff-203
Requester chest checkmark: https://www.factorio.com/blog/post/fff-222