The all-in-one tool only decrypts Widevine L3, which is the lowest security Widevine protocol according to TFA. 4k content is only available with Widevine L1. The others don't say which level they support, but I assume it's the same.
That tool says it does for 4k for HBO Max. All the other platforms (Netflix, Hulu, Amazon, Disney+) are 720 or 1080 though. Wonder whats going on there.
