this will seem like a crazy statement
in no way shape or form should the clean up crew be the deciding factor on when/if you get green hair algae or any other algae. the reefing world has a serious, serious, serious problem with algae still wiping out $5000 aquariums even though there are 30 yrs of books and articles on how to prevent that (they don't work very well, outdated info)
in any algae book, the opening sentence should say
if you see algae, kill it the first day you see the first sprig, clean up crews and nutrient controls are -hopeful- preventatives they have nothing to do with whether or not algae is in your tank. If they work, great, you'll never see any algae. If they don't work, you'll see some algae, and if you leave it in place expect to have about a 60% chance of never regaining or going long periods disliking your reef and making excuses for it to anyone who sees it.
There is one cause of algae in the marine aquarium, purposeful human farming and nothing else. We see algae, we are told to leave it, act on the water, we do, and my peroxide threads grow by leaps and bounds. Please public keep following the incorrect advice from the last 30 years I cant get enough after pics. but willis I hope you do not ever let algae in your tank, the cuc is there to hopefully eat it and make it not seen. if you are seeing it, it means they aren't working, and you need to