At the stage of the game where science/workshop tab items cost 85k science, it appears that all science is continually used to craft compendiums/blueprints. The accumulated science is always spent on crafting, and the new science/workshop tab items are never purchased.
Even when opening the game after a period of time and having full stocks, it is spent on crafting before science/workshop items are considered.
Looks like crafting is done at a % of full stocks for each resource. Everything progressed after stock maxes grew and 85k was lower than this threshold.
At the stage of the game where science/workshop tab items cost 85k science, it appears that all science is continually used to craft compendiums/blueprints. The accumulated science is always spent on crafting, and the new science/workshop tab items are never purchased.
Even when opening the game after a period of time and having full stocks, it is spent on crafting before science/workshop items are considered.