Beautiful Boards Mike! As always, your work amazes us.
With that size and thickness, it might not require recesses for finger grips.
I would make them and hold them, flip them over in your hands. Simulate
if you would grab them and carry them to the counter and set them down.
If you feel that the recesses would help in the use, by all means add them.
You need at least 3/4" recesses to get fingers inside without binding. It
might not leave much material left, on either side. Just something to consider.
Thanks for posting!
Ellery "Bud" Becnel