Evan, you are the man, thanks for this! It’s been years since I’ve used Transmit and I had no idea this was possible.
The backup solution I ended up going with was S3 and Arq (http://www.haystacksoftware.com/arq/), something I HIGHLY recommend as it has saved my life on more occasions than I care to mention. Arq is a one time $30 license, but it’s completely worth it. Gives you the ability to enforce your S3 budget, has fantastic file versioning, and gives you control over backup timing sched.
Hope this helps!