For the long time I played Warframe I noticed that I have to spend way too much time before a mission to do the same stuff over and over again. If I have to change my loadout, that unsurprisingly happens a lot, I have to go through a lot of animations. I think it can be impoved at by adding a few extra buttons next to "Upgrade" and "Appearance" buttons. These extra buttons can either be there at all times, or hidden, appearing only when you when your cursor hovers over the respective button. Upon clicking one of these extra buttons you will instantly change your loadout without any animations, and for weapons/sentinels you'll also be able to quickly copy your Warframe's colors to fit its look. A feature like this would make preparations significantly faster, as you wouldn't need to open extra windows just to choose one of your pre-build sets.
If you think that this feature is usefull for you, Tenno, please, let me know in the comments, as I'm genuinely curious if you'd find that useful. Doing so will also help this post gain attention.