We do need it.
The problem was that when getting the bone length, you checked if the scale > 0 and set it to zero otherwise.
It's a simple fix, if you want to add it to your project
Viewing post in Ik solvers doesn't work after changing scale to negative value
Ah, neat! I appreciate you letting me know and I can pull it into the project and release it as a bug fix (with proper credits to you for finding the fix 🙂)
Edit: was going to try and get it over the weekend, but other things came up and I didn’t have time. Will try to add it in this upcoming weekend. Sorry for the delay.