If it was mere volume it might still benefit us for there to be a standard rate, since it would reduce the barrier of entry for competitors. Of course they aren't competing and they aren't shipping to the same standard, so it's moot.
Where graceful means it uses a redundant array of drives which can fail in gradations rather than preserving either 100% or 0% of the data.
D-GRAID is an old concept ... but I see very few implementations. Basically there is unRAID and WHS with mirroring (and a couple of hacks you can do with...
You can boot this off USB http://ubuntu-rescue-remix.org/
It also has some hints on how to use ddrescue here https://help.ubuntu.com/community/DataRecovery
3ware has an ignoreecc command line option for rebuilds, but I don't see anything similar for Areca.
If you have a spare drive and know your way around linux you could try copying the drive with dd using the option "conv=noerror,sync" and using the copy for the rebuild.