Mickey, I’ve read that peeling vegetables & fruits does reduce the fiber, and so does cooking. Unfortunately most of the data I’ve seen doesn’t seem to reflect that.
For nut butters, I don’t think nuts like almonds are blanched (peeled) first, so I don’t think the fiber & FP would be different. I thought the higher GI for peanut butter was because most have added sugar.
However, you can buy almond flour without the peel.
Almond meal usually means the whole nut, but if the nuts are blanched first it’s called almond flour. Read the ingredients to be sure.