Art files XML are not working in mod units

Hello,

I have try to use the Resource manager (v0.7.0) to extract and edit XML files from art folder. My goal is to edit these files to generate a new character capable of multitasking and having multiple abilities. However, when creating a new art XML file and adding that file to the corresponding line in proto_mods.xml the game does not read the file (the character does not appear anymore). I have tried to convert this file back to XMB, but even if I do not edit anything in an XML file (for example arkantos.xml) when I try to convert this file back to XMB Resource Manager does not do a good job and the file is not exactly the same as the original, so it makes me think that Resource Manager is not working correctly for the art files.

Has anyone tried editing these art files and had the same problem as me?