I did the search for definite answer with no results. It seems, that this bothers only us, keepers

.
Only brief mentioning in
S. D. Cairns article:
colonies of interconnected polyps
But take a look at my sun (it was before fragging).
This colony:
grew to this:
With no place to grow further (it was moved frequently during cleaning):
it started to grow, covering the bottom part, that wasn't accessible for a feeding and therefore was never fed. Polyps were alive and colony continued to expand:
Note ruptures from the moving: still no infection or necrosis.
I gave up long time ago with trying to feed each polyp, but trying start to feed each time from different place, this way probability that most polyps will eventually receive their food will be higher.
But those, who are using bottle feeding or
Lunar Lander shouldn't worry, all polyps are covered
