Loading Screen Connection Indicator
Too long have I and other gamers suffered when somebody/multiple people disconnects and you sit there awkwardly at 100% and wonder if it is your client that is broken or someone else. So you restart your computer only to find out the enemy mid laner disconnected and you wasted the first 5 minutes staring at the load screen.
I want to suggest a green/grey light indicator that turns grey if the client is unable to receive information (disconnect). This way you can know that it is not you that's the problem because your light is green and it's better to wait it out!