I think I've found a spot that could work for this. Just tested it out on Yacumama, which was really, really easy. It basically glitches and runs around in a huge circle rather than cutting corners. Was plenty to get nukes off on Yacu, should be ok for Krab too, hopefully.
Took a pic of it afterwards, demonstrating it with a normal mob. NMs will take the same path though.
You can also go closer to the middle part of the fence and have it melee you from the other side (although it will look like it's on your side, it's not), where you can get a nuke off, then take a few steps back to make it loop around again.
I'd imagine this would be the most favorable spot for Krab, as it definitely made Yacumama a joke.
Edit: Also, I didn't see this mentioned in the thread, but I soloed Skuld earlier. Pulled it to the lake in Rolanberry and kited it around as RDM/NIN. Took 60 minutes with Bio II/Poison being on most of the time.
You have to be careful though, because its Bind/Gravity can fuck you up. Need to time when you stop to cast on it, as it can be quite deadly past 25%. Had to tank it a few times, where MDT/PDT sets pretty much made the difference.
Not a terribly hard solo though. It was a joke pretty much until 25%, where it starts to near-instant cast.