It seems much thicker than Staghorn Algae? Search out some pics and see how it stacks up.
Personally if it is a cool think I hate just randomly killing stuff in the aquarium. But cool could also be a pain too, BBA is one.
So the good news is if it doesn't seem to be a problem, it doesn't seem to be an emergency. So a few days or weeks to figure it out maybe. Also sometimes wood grows stuff and after a while it just disappears. My daughter had some growing "mushrooms" type things. So it is also possible it is a fungal growth. That doesn't necessarily mean a bad thing.
And it can be killed if needed.