First of all, thanks for creating this mod overlord!
Every command works as intended but I've noticed a slight bug or something of the like with the spawn planet command. The first time I use this command and colonize the planet, it works -- however, when using this to spawn a planet the second time on the same system and colonize it, for some reason it bugs out and the planet does not function properly as a colony (It doesn't appear on the colony overview, you can't build as the timers were frozen and what not).
So basically, when you spawn the first planet on any system and colonize it, it functions as intended. However, when spawning a second planet on the same system as the first and then colonizing it, it just doesn't function as a colony.
I just came to report this same issue for those who use this mod. It appears that irrespective of what name you give the planet in the spawnplanet command, the game will always know the planet as "planet_0", you can see this when you fly up to the planet before colonizing it (the name you gave will show up correctly on map views though). This is fine as long as you don't add more than 1 planet to a system, in that case it seems that both planets are regarded as "planet_0" and the game gets confused. If you abandon one of the planets, all other spawned planets in the system will also be affected in some way, as the game can't seem to differentiate.
Edit: Good news, this problem can be fixed through save editing:
1 - Create all your planets using the spawnplanet command.
2 - Take note of the names of any of the pre-existing planets (not ones you have spawned), or if you there weren't any colonize
one of the spawned planets and use the colony name.
3 - Use "save copy" to create a new save file.
4 - Go to campaign.xml (I used notepad++) and search ctrl+f the name of a planet in the star system.
5 - You are looking for something like "<id>market_system_2f24:planet_3</id>". Ctrl+f on "market_system_(SYSTEMID)" in my case allowed me to easily move between the planets.
6 - You need to go through all of the spawned planets and change their planet id from planet_0 to something unique. In my case planet_0 and planet_1 were the pre-existing planets, so my
two spawned planets became planet_2 and planet_3. (You might also wish to change the associated <name> tag which will also be "planet 0")
7 - Once you fix all instances of duplicate planet_0s it should work just fine, as the game can actually tell the difference between the spawned worlds.