When putting more than one of an item in a single slot in a block placer and then giving it a redstone pulse, the block placer will place the block, but the entire stack will be gone. I.e. put 30 dirt in it, give a redstone pulse, 1 dirt will be placed, 29 will be gone. Putting items in separate slots works as intended. Using the latest versions (1.12.2-4.8.6.74) of the base, mechanical, integration and fabrication mods.

Fixed via 4d34254