It would be nice to be able to add SSH keys with read and/or write access for repositories, not for the whole user.
Use cases would be read-only keys for services that pull the code (mirroring, pull-based auto-deployments), multiple development machines for different purposes, or work/private distinction.
++. leaving a comment here because can't subscribe to issues the other way
Same, unfortunately
Aren't these use cases already served by the existing functionality?
For read-only access you can use git or HTTP protocols. These don't even need an account on Tangled, they can be unauthenticated.
And for work/private separation, you can add an extra account to your account list.
+1, scoped/fine-grained auth should definitely be a focus