Actually no, there's a reason loadiine won't work, because you need to be able to install persistent stuff (IE patching coreinit's start function to run code when you open an app like Mii Maker) and that requires kernel which isn't public on 5.5I will be back tomorrow and will then look further into the elf loader. Also I don't think that there is a problem with the elf file, but I will compile it again and see if there are any differences.
Atm the elf loader loads the payload from a Webserver, but it i'm sure that it can also be loaded from SD with a bit of rewriting.