Many of us don't use the web browser for selecting addons and missions and such, so logging into steam in the web browser is a bit of a pain. It would be much more efficient if it took you to the Steam App instead.
- Legacy ID
we've got some hints from Valve support staff and managed implement this, albeit it is using commands that are not officially documented by Valve.
We're pushing this change into the development branch today, but there is no ETA for main branch.