Some mods adds very small stack sizes (20 for example) that you need to input into very hungry machines, so we need to request more items to buffer before next update ticks so there's no bottleneck.

I noticed that logistic requester chests automatically grabs items available from the network but only 1 stack at a time at maximum. Is it a bug? Is there a way to increase it? It happens both with IN chests and logistic chests

duplicated, please remove

Do you have a link to the issue that this duplicates? I think this is a new issue.

One potential cause for this is that you only store one stack of the item in the Item Network. This can be checked by opening the Network View (ctr+shift+N) and looking at the item count.

My guess is that the item count in the network in your case is 20.

If that's the case, you should raise the limit on all chests that provide that item to increase throughput.

sorry the "duplicated, please remove" is that my browser posted the same thing twice.
And yes, network has less than 5k which is the hardcoded limit I set but the chest only fills up 1 stack of the item.

First image shows the requester situation with the provider ammount defined:
https://prnt.sc/uATXYhzoiXUz
- as you might be able to see, the line is backed up, first 8 Centrifuges aren't working due to clogging, but network has less than 20 items

Second image shows the current ammount of item in the chest and network contents
https://prnt.sc/cVE9aBpzDJud
- I think the chest could be able to fill all the available slots and send it into the network, so we could improve on UPS saving by having less IN chests in the world.

Thanks for including the images. Why does the provider chest only buffer 1 item at a time? Have you tried raising that buffer?

The buffer of 1 is just to "if full, don't waste item on top of the chest", useful for malls and expensive items like sattelites.
I'll try raising it, see if it changes the behavior

Just confirmed that increasing buffer also allows more items to be put into the IN Chest, but feels wasteful if network count meets the criteria... Maybe could there be an option to tweak this?

What specifically do you want to tweak? In general it's pretty standard when using this mod for the buffer size to be 0.5->1 x the number of items stored in the network depending on the number of providers and requesters. This ratio of buffer / network count comes from how network chests are updates so it might not be possible depending on what you're asking for.