I also use starsan and it’s mostly a contamination concern if you ever get the liquid drawn through the airlock into the fermentor (like when manipulating plastic containers and such). So far I’ve seen some dead fruit flies in my starsan up there for longer ferments and still no issues with the resulting beer.

OP does say he uses a different sanitizer further in the thread, and that is less stable than phosphoric acid so there’s a chance it’ll just turn into water at some point.

Still, homebrewing is mostly about having fun with it, so no sense overstressing about ir.