So your stance seems to be "It's okay to fund Nazis as long as you like what they have to say about the trains running on time."

I understand that you want to defend you business and your friend, but signing up with the Nazi party means you sign up with all of it. I find it highly unlikely your cofounder was unaware of the rest of the racist and viscous rhetoric when he opened his checkbook to buy the party the equivalent of a house.

Mullvad likely makes good money, but thats not a casual "I read this one article and didn't look into it deeper" kind of donation for anyone.