aye, where do you draw the line on cloaking? (what's the current max scan?)
a mega colossal (81 spaces) filled with nothing but cloak (11 inverse flux sats, 2 chron shifters, 1 modified grid pylon, 1 silthion gas vesicle) gives you 9.7K cloak, 200 def, and +4 research
(not counting any passive cloak you might have or put on the planet)

naturally anything smaller than megacolossal won't even get that much... and i doubt there's anyone out there that has nothing but MC sized planets

Yeah, I mostly rely on passive cloak and special structures, the researched structures don't seem worth the space.

As an example: I am only Rank-140'ish currently - but in one of my recent scan blitzes I found an Aphotic Plane with passive cloak of 1.2k (around 2.4k after legion bonus).

Tip: only planet SIZE matters in the long run once you start to collect a lot planet upgrades. That means gases to plasma. Of course in the beginning that's not possible, so get large+ at least.