I've been trying my hand at multi-homeworld because of the new multiple energy reactor buff. Its actually quite a bit of fun. I've noticed it makes offense a lot easier and defense only slightly trickier.
My first attempt was a 7/7 3 star game that I went with two neinzul bonus ships and played a low-aip game thanks to being able to send carriers everywhere to eliminate data centers and co processors early in the game. I ended up quitting that game though because I foolishly alerted a core world waaay too early and then bit off more than I could chew when I tried to cull down the number of ships on it. I seemed to have forgotten the lesson I learned a long time ago that you dont want to free 300+ core bombers if you're not ready for them.
My current game is another 7/7 3 star game on a lattice map with FS enabled and +300% resources. It is a ton of fun, and does have the feel of an all-out war.
The trick to these multi-homeworld games seems to be not letting yourself get caught out of position on defense. Offense is ridiculously easy with such high ship caps, but with larger waves and especially the brutally oversized exo waves, being caught unprepared or out of position will cost you the game, even with a resource handicap.