@忆无心（Yiwuxin)
On average, usually between a half hour to 45 minutes so the ambushes don't become overwhelming. It's also random whether they'll be friendly or not. :)

This MOD is so interesting. What is the interval between ambush events here?

Yes, it goes by planet threat level rather than planet names, so it affects modded planets as well. The only planets that the code tells not to spawn the ambushes are Barren and Garden planets, and regular, airless moons are also exempt. Planet-like moons still have ambushes. The stronger version of the enemies only appear on planet threat levels 4 and up.

Does this happen on every planet vanilla or not? Aside from the exceptions of course.

omo