Looks great Scott!
Given your close encounters of the rattle snake kind have you ever considered screening the inside of the drainage block?
This is what I use.

I also use a commercial, brush type sweep, on the bottom of my gate. Neither of these add ons are visible from outside the wall or gate.
Early on we had two rattlers in the backyard, one under the love seat by the slider!
None in the backyard the past 8 years.
Your courtyard is beautiful but I’d hate for you to consider it done.
Jim
Charter Member of Team Gravel.