First off, I have installed and tested this set in my Boss... er, the wife's Boss first.
Here is the thread on that: LINK
There are more pictures of fitment and details there.

This is how it came:

Since I always run in parallel, I decided to eliminate a connector set:

I also shortened the harness so that the wires tuck under the body nicely.

In order to program the ESC with the card, you have to unhook it from the Rx. I do not want to have to pop open the Rx box every time I want to tweak the ESC... so I eventually came to this as a solution:

I tried soldering a servo wire in parallel, but it actually must be unplugged to be programmed.
This also makes the ESC easy to remove for water clean-up, as it is not waterproof.
(Once my JST connectors come in to unhook the on/off switch)

Here is how I have mounted the on/off switch:

Notice the angle on the cuts in the top picture.

To be continued...