When I started to upgrade my warehouse to tier 3 (which requires more than 1000 planks), I have seen the builder requesting only batches of 10 or maybe 20 planks at once, which is quite heavy on those deliverymen. (especially since they were only 2 at this time).

I would suggest, that a builder should always request either a full stack of the material if a full stack or more is still missing (he does that sometimes only), or the exact amount required for the current build.

The builders will actually request 64, if they need 64 or more for it. However, depending on how those are spread over the warehouse, they might get a stack of 20/30 and not the entire 64. This is already in #4535. To make sure they pre-request the actual quantity they need so dmen can fill that up.