Honestly, I'm just a lazy developer. My program, Keyhunt, isn't even optimized for GPUs yet! After more than three years, it's still riddled with bugs and quirks. But hey, despite all that, it's currently the fastest Baby-Step Giant-Step (BSGS) implementation available for CPUs. Not bad for a hobby project, right?
I am also lazy and I made the fastest (for now) implementation of bsgs for gpu. The difference between us and him is that we let people use our developments and sources, but he does not. If everyone sits in their own world and does not share knowledge, then there will be no progress. And this applies not only to him, but to others as well.
As far as I understand, for both low and high, the code that implements the key search most quickly on specific equipment is suitable everywhere. Earlier, when I was in the subject and tested the fastest codes for searching were from the author of JLP, due to a long absence, I can not say exactly what the situation is today, with programs that are freely available.