> Keeping it to Mac/PC only does make Linux, NAS, Server folks unhappy, but thus far no one has been able to crack the code on an unlimited, fixed-rate service that can back up those devices economically, but if we figure it out we'll let folks know

Please do! I really would prefer to use Backblaze.

In the meantime, CrashPlan for Small Business is an unlimited, fixed-rate service that supports NAS backup on macOS and Linux. I depend on it to backup a lifetime of photos (100K+), for example.

https://support.code42.com/CrashPlan/6/Backup/Back_up_networ...