Currently the void upgrade only allows for void all or void overflow but only for a single slot. A third option (or a rework of the second option) to void overflow only when there is no more valid space for it would be useful. For example, my usecase I have slots reserved for each output type from a botany pot, but it starts to void once only a single slot of the multiple slots set for a specific item is full (example, I have 10 slots reserved for logs, it can start voiding once just the first is full). The ideal interaction here would be it only starts voiding once ALL of the slots that it can fill are full.

I have this one on my list of future enhancements so I will keep this ticket around until that is implemented.