I've already unpacked ALL files, I always unpack to romfs-folder, never to romfs.bin (for unpacking I use NCA-NSP-XCI_to_LayeredFS_v1.6).
I found many interesting files like a lot png's etc.
But no loading screen picture or a folders name giving a hint about it.
As I've told you, There's no standard for these kind of stuff.
It's in romfs section but I have no idea where it is