In short, I don't want to have to work through a Sector.yaml file placing all the playfields. Even if they were random generated playfields, their number and position would be fixed. I've got the playfields set up, all I need to do is get the Sector.yaml file to use them, or to somehow use a tuned version of the solarsystemconfig.yaml file.
Yes, you can edit the solarsystemconfig.yaml file (I suggest copying it and renaming the copy to something like solarsystemconfig_YOURSCENARIONAME.yaml but you do need the file to start with solarsystemconfig for the SSG to recognize it usually). You can then edit it to your liking, adding custom planet entries that use your playfields. You can also use the SSG itself to create a custom config file, which might be easier. I made a scenario which is designed to be used with the random generator and there's really a lot of cool things you can do with it to control how it generates a random system, but depending on how many playfields you're thinking of adding it might be easier to manually create the solar system. Warp lanes for random generated maps can be a bit wonky.
Thank you so much! I've got the play fields, which are the standard random ones, but with a better distribution of resources. Do I leave the solarsystemconfig.yaml in the random generation folder where I found it, or do I move it to the senario, if so, where? SSG crashes on launch for me, so it's not an option.
If you can't use the SSG then you can edit the file called solarsystemconfig.yaml and leave it in the default location. That is the file the game uses when starting a new Default Random game. So just edit that file and then start a new game using the Default Random scenario and you should get your custom solar system.