Ok so I'm using CTFtool v5 beta2 works up to 6.39 after you make the tex logo.png at 6.39 convert that file to 6.60 explained in previous post at beginning of thread. I believe I will still help if there are issues and still looking into this more just posting what I have so far.
CTFtool by PatPat v5 beta2:
http://l-patpat.cn/release/CTFtool_GUI_v5_beta2.rar
Edit: my boot file is a .png (RGB, 1 layer) 218x14
After your file meets that requirement convert file back to .gim with CTFtool

let me know if this helped at all