Disconnecting BLE after download, client side and device side

seems to stay connected after CLI has completed

eep. I don't have any suggestions - that's definitely not the intended behaviour! I'll take a look when I get a moment.

On the device, how can you see if you are currently connected?

It's the slight;y cryptic NRF.getSecurityStatus().connected - http://www.espruino.com/Reference#l_NRF_getSecurityStatus

You can use that on a central connection as well if you need to see if that is connected.

If I do want to force a disconnect from the device side as part of my application once programming is complete

Yes, NRF.disconnect() as the last line sounds good. In an ideal world the CLI would automatically disconnect though - I'm a bit surprised about that!