Just some quick feedback:
I found that with v3 I had to eliminate the new pressure curve setting (flatten it) in order to get decent control using the Seaboard. The idea of the pressure curve seems really useful, but I'm hoping that the team will put out an update with better default settings. Again, this is probably specific to the Seaboard default settings—specific to the nature of the input device, I expect.
(I also made a separate post about a terrible "stuttering" input issue I'm experiencing. Hoping to get more eyes on that post. Thanks!)