Locking a version can be done through ynaptic. I think adding this feature to Seftware manager would make things easy, as we can freeze ther version immediately after installing any app.
To add to it, freezing an app would automatically freeze the dependencies solely depending and to be used for that particular app.
If the dependeicies are shared, and the newer verison of the freezed shared version is available, then a notification should be should so as to avoid conflict.
I do not know how feesible it is, but it looks like it's complicated, but currently, Software Manager is being updated and I think it is the right time to throw Software Manager Related ideas.