I think what's been missed in the responses so far is the fact that under the new compiler the source code will be stored in plain text format, the same as all other development IDEs. The ws_objects folder isn't where PowerBuilder stores source code, it's just where it exports it to when it does an interaction with source code operations. That means you're still limited to using the PowerBuilder source code control options. That folder doesn't get updated until you perform a source control operation through PowerBuilder.
With the source code stored in plain text format you're then free to the source code version control tool of your choice. We use bitbucket for source control, but for all my non PowerBuilder work (and my PowerBuilder work that doesn't involve PowerBuilder source code) I use Github Desktop to manage branches, pulls, pushes, etc.