If you’re too busy, din’t feel compelled. There’s a lot of material. Here is a decent place to start: https://www.youtube.com/watch?v=Pmz10uQsTYE

You’re right. FFMI is not the same as BMI. FFMI is actually a good correlate for how muscular someone looks.

Check out the work of Dr. Jonathan Haidt.

Thank you for your hard work. It’s amazing how well things have taken off here. I wish you well, and good fortune to the new brass.