Sorry Ben for the delay in my reply, I’m having a lot of work these days, with almost no time left for anything else.
About bp thickness, it varies between 3 and 4 mm. I found that a good tradeoff between thin bp and heat spreading over the base.
I agree that the turbulence and “aerodynamics” part is the more intuitive in my block design; I want to do a similar base without turbulators to see how much they impact.
See you’re burning your brain with numbers in your design

, I opted for a theorist approach in mine and then test run different base configurations, it’s very easy to exchange the copper discs.
I’m almost done with my block, hope this week end have some time to make the clip

. In the meantime here’s how I’m going to merge the four outlets: