As KSK said, the interstellar part is not really KSP for me. I see something more science and exploration oriented. (n-body simulation, life support, biomes and special places to visit)
Maybe the possibility to change the solar system to have other challenge and worlds to explore.
Also a support for extern programing language like Python can be very good.
I play only on Linux. I really hope KSP2 will be supported also on Linux. I will stay on KSP1 if not. I have some fear with the EPIC's politic... They don't like Linux and love micro-transactions... KSP is a fabulous game. Don't kill it please...
