Now that the moteus-n1 is finally released, I've documented the test fixture I made to perform end-of-line testing on it.  Most DIY test fixtures are clamshell affairs that can probe the top and bottom of the board.  This is 5 sided, probing top and bottom, as well as 3 of the 4 sides in order to test the right angle connectors.

I've got a longer writeup showing how all the mechanics work up here: https://jpieper.com/2023/07/15/5-side-pcb-test-fixture/