The flipper looks great! Agreed on the fiddliness of building ants. I think the layout will get easier after a few goes but I'm also struggling with the tiny solder pads.

I saw the nano ESCs on the BBB shop, it'll be good to see your test run. For our ants I've come up with a halfway house using one of these taped to the standard dual-channel ESC. Saves the weight of the wires and connectors at least!