Carna looks like a great mod but it right now spawns literally on the right on top of a bunch of other planets and having the inability to manually switch it's position is the only thing that right now is stopping me from playing with it.
https://mods.factorio.com/mod/carna

Added

Thank you

BTW how hard is it to add new locations? Cause if it's like 2 minutes of work, could I request adding ___ as locations?

https://mods.factorio.com/mod/VoidProcessing?from=search - This is an expansion that is not finished but adds an end game black hole you can travel to, it
has two locations, the black hole and it's approach.
https://mods.factorio.com/mod/deep-space-encounters - This is a completely new mod that adds something... If it takes a while to make these custom
settings this isn't necessary but I feel like it's better to have more control than less.

No, I made functions that works like easy configuration fetching, everything that I need to know is mod name and actual location name (can be viewed in debug in-game, under location), but usually I open mod files and search in prototypes files for exact location name. So, the config looks like this:
{name="carna", mod="carna", radius=0, angle=0},
If you are familiar with lua or any programming language and you want to dig deeper, you can look at the repo Better-Planets on github (link in bio), config.lua file.
I added your requested locations, but positions for them I set 0 (I don't know where they supposed to be) and they are disabled by default, so you can change them manually as you wish.