I think you might be running in to a Freya specific issue here. In general a 30gg and a 32g should have the same volume, and the wires in most brands should be very similar too as many brands use the same ones. So you should not get 4 boobs in a 32g but not in a 30Gg, although I wouldn't be surprised at it nor being totally flush at the gore because the band won't be as tight. The other possibility is that you're compensating for the too loose band by tightening the straps which might create 4 boob.
However...Freya changes a lot of its bras at a gg. So you will get a bra with the same name but a different cut when you go from a g to a gg. The gg versions, where they change, get thicker straps, higher gores, and 3 hook bands as a rule
I remember now that she kept telling me to essentially let my boobs drop in to the bra. Like pull the cup away and let my breast tissue shimmy down a bit (I had already done he scoop and lift). Which helped but I've never been asked to do before at a fitting.
My boobs are still pretty full and perky ish after Kids <stealth boast> but finding a bra is a nightmare.