Probably higher than you’d think since they’re designed to loiter over inhabited areas and provide connectivity…
Position-only flights are hidden by default unless you explicitly ask for them through your account settings, because there’s a lot of noise in there which can be confusing. When we can infer a reasonable origin/destination (generally, after arrival) they can get upgraded to regular visibility.
Cocos only has about 500 inhabitants and has good phone and internet services and it seemed to me to be a bit of a waste hovering a balloon over there.
It looks like it may be changing altitude to stay on station.
I have section 6 Position only flights set to show but i couldn’t see it until i was told the balloon’s call sign as seen on the Skyview screen locally and i could search for it.
Apparently a couple on the island are out trying to spot it but i haven’t heard if they have seen it yet.
It is just getting to sunset there so that may help.