jdflasher only supports cid53. And at present you cant back up a cid53 gdfs.
However if it does fail D-Unlocker has the ability to repair a corrupt GDFS.
Here
you can flash your phone with different firmware and custom packs etc.
At present that's about it until a new version of xs+ is released.
To be honest you say your new with SE's. IF your phone is working and your unsure then dont do anything.
Lavondys