I found this out yesterday indeed, that they have removed BinaryFormatter from .net 6 completely. This is problematic as the profiler's data transport is based on binary serialization. So fixing this requires the redesign of the data transport system. It's a lot of data, so the first alternative, json serialization, is likely going to be a terrible choice. So at the moment we don't have a solution, we have to look into how to fix this. There are some options...
We'll try UTF8 json serialization first, to see if that is doable.