Minecraft wiki entry for Development_versions, associated text: Recipe Select button prompt shows when hovering over a non-craftable recipe book item using controller (MCPE-79725).
Recipe selected items put in crafting input grid can now be hovered over with controller to see their tooltip names.
On controller, hovering over recipes will show them in the crafting grid when no recipe is selected.
On controller, you can deselect a selected recipe when hovering above that selection in the recipe book. You can also clear the crafting grid by clicking the right stick.