In that case, I would suggest that for the Desktop app, you simply use the existing Feature Request thread to vote for or otherwise support this feature.
For the mobile apps, you can start you own feature request (which I suggest you title something like “Specify Default Browser for Launching Websites from Mobile App”). To post a feature request, please use this link to access the Password Manager Feature Requests section of the forum, and click the + New Topic. For the topic tags, make sure that you select app:mobile and cloud-default.