Viewing items will re-create crafting inventory for every single item (that has a recipe that uses it) viewed, even if the inventory doesn’t change (for example, when picking an item to craft or just scrolling an item list). The time to view an item is now comparable to the time to open crafting menu, which in big crafting rigs can get HUGE.
Even if the crafting inventory was to get cached, I’d rather have an option to turn this display off. At least the graying uncraftable things part - just listing recipes doesn’t take much time, as evidenced by items that lack recipes associated with them (no recipes = crafting inventory isn’t built).