Current state, vacuum hoppers are almost unusable for farms since they need solid blocks all around them to stop light getting through. Because of that, you cannot connect pipes, fluid hoppers, or anything else that allows the passing of light. This could be fixed if the vacuum hopper was capable of attracting xp and items across blocks, however, one face of the hopper has to be exposed to where items/xp is dropped otherwise it will not work

This shot shows items and xp not able to get though the block to the vacuum hopper, even though they are being attracted (there is a torch behind me for some light)

Here the VH works as intended, but it has stone on all sides except front

Even so, some items get stuck on the spikes. This could be worked around by relocating them

This is with a fluid hopper underneath connected to a tank with xp. The fluid hopper allows the light from the tank to get through so it goes through the vacuum. There are no torches or light sources anywhere in the room

This is the other side without the stone blocks covering the vacuum and all around tank and hopper

Hopefully, something can be changed so this can be useful for mob farms. Thanks!

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I would also add a suggestion to allow the vacuum hoppers to be configurable both in their range of pull vertically and horizontally, as well as a blacklist/whitelist filtering option where you could lock the slots to only accept certain items or to not accept certain items.