Hello,
I just finished building this simple tool: https://github.com/Nax/FFT_Decrypt/releases (https://github.com/Nax/FFT_Decrypt/releases)
It can be used to decrypt EBOOT.BIN in-place in the WotL iso.
The main use case would be to implement this suggestion (http://ffhacktics.com/smf/index.php?topic=11915.0).
It's very simple: you select your ISO and click "decrypt" to decrypt EBOOT.BIN inside.
The tool will warn you if the ISO is not a valid WotL image. Also, it will warn you if it's already decrypted (but you can force the decryption anyway).
It work on E and U ISOs.
Enjoy!
(https://i.lensdump.com/i/xF4ST.png)