Short pigtails permanently attached inside the shield and mounted on the shield is how I would do it. I am just concerned about the heat buildup inside.
Me too, which is why I haven’t put together a fully sealed box yet.
I am thinking that I might go out into the workshop and mill me up something similar to one of these and see how it does:
I have one for my Pi3 and it works like nothing I’ve ever used before, never gets above ambient temps no matter what I do with it. Might just be the ticket for these boards.