So what's the best way to cloak/defend 15x mega rich VL toxic planets?

just curious as recently I had 2 tough ones with minimal cloak get taken recently.

Up cloak as much as possible. For example up the passive cloak to max with Interspacial Fold Generators, but that's just a start. Then up it even further with Magnetosphere Chargers to the max possible. If done right, you should have 3500 PASSIVE cloak, then put artis on the planet that boast cloak even further, preferably ones that increase cloak by a percentage to get the most out of planetary space.

Don't worry about perma cloaking a toxic...
Save that for arti planets.
handful of obv barriers with a decent legion bonus should do. Maybe barrier nexus' of you have too many silvers.

have been using barrier nexuses to try and reinforce those planets

thoughts on a Topopolis given the space it uses??

No point max toxics are fairly common when you get to high ranks 2 star lifters any mineral arties you have on the planet and the rest put obv barriers no need to any more than that.

my 18X irradiateds all have betweek 8-18K combined stats, heavily favouring def over the attack, the att on the planets always comes from tri/phase cutters(ive never seemed to get enough to fill all my planets with them), and any cloak on them is never from something ive put on them, and the one with the most cloak has under 2K on it.

I have 2 obviation barriers on mine and I just regularly flux probe/temp flux them if need be. I have enough mining that if I lose one, I won't cry about it.