Well, I've continued looking, but either I'm the only one having this issue or I'm the only one who cares.
The answer from B&N is to eject each drive (nook & SD card) separately from the file explorer.
The answer from Microsoft is 'Safely Remove and Eject' from systray.
The programmatic answer from Microsoft is CM_Request_Device_Eject()--which calibre already does and is equivalent to 'Safely Remove and Eject'.
All I've come up with so far is that using PowerShell I can do this:
Code:
$o = new-object -com Shell.Application
$o.Namespace("G:\").Self.InvokeVerb("eject")
$o.Namespace("H:\").Self.InvokeVerb("eject")
I'm trying--with little success so far-- to lift code from Open With to run a PowerShell script from SmartEject.