Just the other day I had a similar conversation.
I wasn't able to find actually scientific sources that claimed or denied bubble algae (Valonia sp.) would spread when the bubble is damaged. It is usually known to reproduce by cell division and budding, but it's possible a cell can recover after getting damaged or maybe even recover from just fragments.
There is also the gametophyte of Derbesia sp. which looks like bubble algae. Derbesia is usually known as hair algae and capable to spread via fragmentation, but it's possible that it keeps this property in it's gametophyte phase as well and then spreads through fragmentation.
In theory this could explain why some people report it spreading after popping the bubbles and others don't, if we are talking about different organisms that most are incapable of differentiating. Even scientist thought Derbesia's gametophyte was a different species and called it Halicsytis for a long time until they discovered it's the same species.
It's also possible that in high flow tanks the fragments get carried away sufficiently to end up in the skimmer, while they can settle and grow in low flow tanks.
In the end, an emerald crabs will also pop the bubble.