small ISP connectors

[IDEngineer]

One downside will be higher board price if i remember correctly, they want more for cut in half plated areas.

Indeed, which is why I said "Its downside is increased cost of PCB fabrication for the castellated edge."

[mrburnzie]

Create pads on the bottom of the board and have it sit on another board with small pogo pins.
That way you can place the pogo pins anywhere where you like. It's smd and can be placed near other components.

[Amper]

"in the field" ist not nailbed terretory.

[IDEngineer]

Had another thought about the edge connectors and their castellated holes. When PCB's are panelized they scribe break lines so the individual boards can be separated after stuffing and reflow. I wonder if you could design the board with "traditional" holes, and a scribe line running through them, such that you could then just snap off the edge leaving the castellated holes as shown in the illustration. That might be cheaper than asking the board shop to actually route and plate the edge of the board... drilling and plating holes anywhere inside the boundaries is just "more holes".

[ataradov]

I wonder if you could design the board with "traditional" holes, and a scribe line running through them

No, it is impossible. Or it would basically cost the same. They normally would not even attempt to scribe over copper layer, much less interrupted cut over holes.