The Numbers are a guide.
There has been discussions around #4 and #5.
here’s Amals description
So yeah, my interpretation would be between.
Also whether a Flex should be on or between bones for a Flex.
People here have had both, including myself.
You will probably get a different answer from everybody you ask.
Me personally, I had better luck between, BUT again this should be discussed with the installer for your specific anatomy.
Sorry that is a shit answer.
Yeah, sounds deep
Personally, I think this will be a good location, with thinner skin and easy to present to readers and get the blinky you are after.
I would just suggest you consider if there is anything else you may want to place there in the future, however, the xLEDs are “inert” so to speak, so they won’t cause you any collision issues, but it will simply take up a viable location IF you wanted to put something else there.