As someone very naive on this topic, can you elaborate on where he pushed boundaries? I follow his YT channel and he obviously pushes boundaries from an activist perspective, and I'm a fan[0], but I'm not able to judge his scientific credentials.

[0] (love that one video where he shows how to get away with replacing poorly chosen non-native plants in public parks that will inevitably die out within a few years with native species that will thrive; basically, put on a yellow vest and dress like a gardener and nobody will bother you)