Simultaneous backup to different repositories?

Apologies if this is already answered somewhere – it seems like something somebody would have asked, but if they have then my search skills do not seem up to the task of finding it.

Anyway, after a bit of experimenting I am preparing to set up scripts for backup to a local hard drive as well as to Backblaze B2. I expect the initial upload to B2 to take a few weeks based on previous experience. If that backup is running in the background, can I still run a separate instance of restic to back up to my local hard drive? Or will the two instances interfere with one another?

You can run multiple instances of restic, that’s fine, even to the same repository if you want to for some reason (at least as long as we’re talking about backing up). It’s just a matter of how loaded your system becomes.