I am surprised this feature isn't already in the game, but I would love to see it implemented because it's very simple and would save a lot of hassle. Many times I have clicked either "Ship" or "Character" and changed around some preferences; things such as guns on ships, or perks or even which class I have selected, and I frequently forget to click the "Customization Complete" button in the bottom right, but instead click "Back" in the bottom left. This ends up reverting any of the changes I just made, and I only discover what has happened after the match has already started and now we're stuck with two buffing engineers on the ship, or the wrong pilot loadout for what ship I am flying.
This could very easily be solved by having a pop-up that says "You have unsaved changes, would you like to save them now? Yes/No".
Does anyone else think this would be convenient?