Sadly, no. Late last year I randomly decided to do a planetary circumnavigation since they were all the rage at the time (ie, there were a dozen or so crazy types like me doing them). I was headed out towards the Prai Hypoo nebula and just picked the first vaguely appropriate moon I came across. Towards the end of that round-the-world trip, the beta arrived with the new scanners. After I finished, I lifted off to orbit and gave the new scanners a try, and lo, there was a bio site. And there were brain trees.Any tips on finding brain trees? They're the only bio I haven't seen yet.
According to Cannon, they are commonly found around big ejecta craters close to Guardian ruins. Since the Prai Hypoo nebula is a hotspot for Guardian ruins, that probably explains how I unknowingly came upon them.