I didn't tried yet as i don't have such a big and high quality SD card as suggested.
What is the scope of dd-ing initram-fs ?
Is it preparing some form of dual boot? should we keep a copy of the previous content?
I noticed in the past that dd command didn't worked in a .oar script.
I think it's because you have to be root and if you launch a .oar script you are just "app" user.