App loader not working

note that I tried for ten minutes to get that BLE tool to 'Refresh' or 'Pair' with my Bangle, with no success

The UI is a bit confusing.

Ignore the 'Pair' button. Click the square with the tablet/phone screen in it. Took me a few random clicks to find it :-) That square is a button, even though it doesn't look like it

Note that (I think) you have to pair the Bangle with Windows first, using the standard Windows Bluetooth UI

also note that the first .png in post #30 now is visible along with the additional image that was uploaded as an edit to that post

Yeah, I was trying random things - they were all showing for me, but not, apparently, for you, so I didn't know what, if anything, would work ;-)