Version: AOF 2.0.6

How to reproduce:

1. Place a kibe cobblestone generator (no matter which tier).
2. Place a Hephaestus crafting station next to the cobblestone generator.
3. Using Hephaestus crafting station left chest window to put a diamond block inside generator 1st slot.
4. Watch diamond block count auto grow to max stack.

You can duplicate any item with this. (diamond block is a example)

sounds like Hephaestus crafting table does not respect insertion on storage or kibe is not doing storage right
https://github.com/Alpha-s-Stuff/TinkersConstruct/issues
The kibe code also does not check current slot contents against the block it is generating so that could also be changed if reported to them https://github.com/lucaargolo/kibe/blob/master/src/main/kotlin/io/github/lucaargolo/kibe/blocks/miscellaneous/BlockGeneratorBlockEntity.kt#L98

both of those things would be issues for the mods themselves to handle

issue was opened 2 months ago, still no fix lucaargolo/kibe#189

Mod issue, pack dev cant fix