They do?? Then they are behaving irresponsibly but not fixing this. I love being able to put out portable PB programs and having no impact on the host system and there is no reason why others can't do it either.They already know that, but so far they have seen no reason to implement it correctly.
Of course not. If it puts gunk into the registry, it's no longer portable and has had an impact on the host. Probably have to reset preferences on every system it is run on then (Just a guess) but it's unacceptable behaviour to do what they are doing, even if it's just a simple "Hello, we were here" sort of thing.You can find portable (virtualized) versions of vivaldi on the world wide web, but this is not a solution for me, because the browser will no longer run natively in the system.
They cannot be called portable with their behaviour.