How to properly pack Awakening images? (For custom portraits specifically)

[Kaii]

So I went to register specifically to ask this question and turns out I had an old account on here already (specifically made to ask one question)! Makes sense that It'd slip my mind since it's from 2017, but I still thought that was kind of funny.

Pretty sure no one actively works with Awakening anymore, also sorry if this is in the wrong category, but I've recently become interested in playing it over and over again and I wanted to make my experience nicer with some custom designs. Problem is I'm not sure how to properly make custom images for Awakening that work in-game, and I can't find any tutorial that's for Awakening and not Fates. I'm genuinely sorry if this has been posted before but I haven't found anything proper. Trying to search for methods lead me to a tutorial on modifying Fates Live2D textures which supposedly worked the same for Awakening according to another forum post I found (If I find it, I'll link) give and take a few steps, but that hasn't worked for me.

The method I've tried based off of that is

• Extract .arc file with FEAT + the ctpk.lz of the portrait I want to edit
• Edit the image, save it as tmp.png in a folder along with the xml file given when extracted
• Create the ctpk file with ctpktool
• Compress the file w/ puyotool (lz11 compression)
• Rename the file to [emotionname].ctpk.lz
• Open the file with HxD, copy and past the first four bites at the start, change the first 11 to a 13 (I thought the image not working might have lied here, so I tried testing this with an 11, a 13, and whatever number FE:A specifically had at the start of their other portraits, none worked)
• Save the files, repack them as an .arc along with all of the other emotions, put them in the game.

As there's no 52 at 0x39 in Awakening's portraits, I didn't change any numbers there.

The game doesn't crash when the portrait is ""loaded"" (I'm using MU/Robin's default portrait as a test so I can see it immediately.) But nothing shows up. Just a transparent space where I should be getting an image.

Anyone know how to do - basically what's said in the title? I don't need a super in-detail tutorial or anything, just some help on where I'm going wrong as I feel like I'm going to keep hitting a dead end using a method for a different, newer game on an older one. The first title is a little vague as I also want to be able to edit the textures of certain models, which I assume is the same process, but It's not as important to me as getting custom portraits.

Thanks a lot in advance!