It would be nice to jot some notes down about a planet. So while in star map i can see what is on that planet that I may have stumbled upon. Such as "big ass castle with hostile knights" and also would let me know if I have visited that planet already.
I agree with this suggestion, but at the same time to play devil's advocate, what's stopping you from using notepad? I think it'd be great not only for immersion, but for utility in-game as well though.
Interesting, I typically opt to play my games vanilla, usually only installing performance mods (like Optifine for Minecraft, or SMIM and SkyUI for Skyrim) but that mod is quite a QoL enhancement.