What would you do with the fastest Kangaroo program I have?
To experiment and learn. I mean, it's impossible that you don't have a faster solution at least for the CPU.
And what is to be learned? Definitely nothing about the 3-kang algorithm itself, all of that is public already. Like nomachine said, one would still need many, many GPUs to find high-bit solutions, no matter how well an implementation is optimized.
The only curiosity one might have would be "why is it faster" or "how did RetiredCoder manage to pull off 12.8 Gk/s on a RTX 4090", which might end up just as a terrible headache reading low-level code, or an "oh", not a revolutionary breakthrough.