I think a solution explorer when coding would be very useful when developing large scripts. This is because large scripts may require a function and an event to be tweaked multiple times, and scrolling up & down can be very inefficient. It would help keep code organized and easy to read. CTRL+F is a good substitute for the meantime, but a proper solution explorer would be very helpful for skimming modules and quickly modifying scripts!
For anyone wondering what this is, here is an example (Language: Java; Program: Eclipse Photon)