I think having a zoom in/out option in the planet selector would be great
[Some times the galaxy may be to big to be framed all at the same time or to small or just you want a bigger picture or focus some area, this situation is more common when we see a solar system, some planets are out of scoop and others are too small, the same happens when taking a look to the moon orbits of a planet.
This could be done through the mouse wheel, it could be a great implementation, it would give us a better control, comprehension and visualization]

fixed in "Advanced Rocketry - Reworked"
(https://github.com/dercodeKoenig/AdvancedRocketry)