Allow to use DOT (.) for Vivaldi accounts
please, could you allow dot (.) when creating Vivaldi account that affects mail address?
It's very unusual to prohibit this sign.
I'm sure that subdomain issue would be minor issue.
And there are not allowed even no other signs as - or _ so this has to have completely different reason.
P.S.: Please, if you are not developer (evev tester which I respect), then I much more appreciate your comment if you like or dislike this feature (e.g. due to reason that blog link would not appear so nice.)