Well I could not install the crashplan plugin and it appears it is very out of date. The only good way is to do a manual installation into a jail. I found some instructions on how to do it but didn't want to spend the time this weekend on it. I ended up just downloading the Windoze version and installing it on my main computer. This computer stays on 99% of the time. Been uploading for 2 days now and have 44GB uploaded. My upload connection is slow. I have about 4 more days to go before I finish uploading my important data (photos, finances, other important docs). If I were to try and backup all my data on FreeNAS, it would take a while. I like using my windoze computer because all of the data is accessible from my main computer and thus I can just use it this way and ensure I get all the software updates as well. Having to install it on FreeNAS means just another software package to maintain.
The downside to placing data in the CrashPlan cloud, it just takes a long time initially due to my slow upload speeds. I'm not sure what other downsides there are other than the $60/year cost but honestly, that is cheap.
And in my case I have weeks worth of work that would go down the drain if I lose my ~12 TiB of files
You generate 12TiB of data a week? If true then I'd think you need to give the software a 30 day trial to see if this would work for you but with that much data per week, OUCH! I'm hoping you meant that you have 12TiB of data and some of that changes over the week, but not a new 12TiB of data total.