I'm going to be straight with you here and ask the UI Team to actually dig out Stellar Reduction when you start a mission that requires you to use Aetheric Reduction to get items in a set time. If anything, there are some people who don't even know Aetheric Reduction exists, so I think it's important that the menu you're supposed to use to reduce the items isn't buried underneath two buttons on the menu.

Do something about it because otherwise players will constantly fail unless they ask people how to do it. On the other side of things, it's just bad to bury mission-important menus in places that are rather jarring.

Instead of Stellar Missions -> Stellar Reduction -> Stellar Reduction Menu,

On execution of a mission that requires you to get Aetherically Reduced items, it should be on start:

Stellar Reduction Menu

Simple as that, and also reduces visual clutter so you're not also slapping the Stellar Mission mid-mission menu there. It's also important to note Crafters don't have to go through this same menu to get to their recipes, even if the button is there in the very same Stellar Mission mid-mission menu, because it just pops up at the start of the mission as it should.