So, did I miss something? I have the "Enemy Spawner Generator" set to Default, with space exploration mod, but I only get protoss in initial planet. Was expecting to have all races mixed, I've started some new games and just enabled cheats and travel on any direction, only toss to be seem.

hm, after some restarts, I notice that it happens much more on rail world, normal SE preset gives normal bitter, but if you move far enough, eventually you find different race.
Not sure if the spawn has changed, I kind liked when we could just have them mixed together, now they seem to only spawn in specific race per bases, even though I have the "Enforce temperature" disabled.
You move, and their is only like big chunk of protoss, rarely some terran, saw just one or two space guys, and no zerg.
Maybe cause SE add the alien biomes... gonna do some more experiment.
I had mainly played with erm and angels, first time experimenting with SE

yes. The default generator has changed recently to accommodate large number of enemy types.

"Default" generator is no longer mixing everyone together. The enemies now spawns based depending on their predefined terrain properties. e.g. Zerg spawn on dryer climates, Protoss spawn on wetter climates.

Here are some examples of default generator with all support ERM enemy type enabled.
https://cdn.discordapp.com/attachments/866511468056412160/1137619440159182918/image.png

https://cdn.discordapp.com/attachments/866511468056412160/1137813411464499360/discord-hot-normaltoxic-zone.JPG

https://cdn.discordapp.com/attachments/866511468056412160/1137815431139299480/image.png

got it. Thanks for the info.
Any chance to have a check box or something to allow the old mixing?