Crafting items upgrades both building and productivity
Play it your way.
The upper limit of productivity is only 200%, they can not increase by productivity research.
This mod never took productivity tech into consideration. recipe.productivity_bonus = math.min(count / 10000, 2.0), where count is the the total amount of items produced.
recipe.productivity_bonus = math.min(count / 10000, 2.0)