It has been a long time and still no support for Vivaldi. I'm not sure why, either. It has a bigger user base than some of the supported browsers. PLEASE add support for this best-in-class browser!
It would be great if you could support other web browsers besides the main four. I like to use Vivaldi but things like search protection don't work with it. So any chance of updating Bitdefender so that it supports Vivaldi?