Noted, but Backblaze's insistence on "simplicity" by obligating a full main drive backup so that users can't later complain that something was missed is silly. Why not just offer this as a default but also offer the choice of creating your own completely custom backup selections, you know, on the assumption that some users of the service might actually know what they want and how to select it.
If you want to get hired by them, propose it, get it approved, implement and test this 2nd code path, and maintain it for foreseeable futures, go right ahead.
Idk about on first run, but I'm pretty sure you can pick and choose which drives it scans, including boot drive, and set up excludes as needed (handy to avoid backing up .git or node_modules)
