Like cfwprophet points out, I'm only editing files not signed/encrypted, which are only the .rco and .xml files. The self/sprx files in the new FWs use keys we do not have so we cannot decrypt them or encrypt them.
It is also for this reason that you can't use a FW loader to give you a 4.11 CFW. Using any of the new FW files without re-encrypting them for 3.55, will simply result in the PS3 crashing on boot. As the new FW files will not be decryptable by the relevant 3.55 CFW Ldr.self
Well yes I can dump FWs like you said, but anyone can do that, with the already available tools.