+ AA6YQ comments below
Sparing the reflector the gory details I need to mark a group of Qs as uploaded to LOTW. Is the Item Name: APP_DXKeeper_LOTW_QSL_Sent
+ Yes; see
+ My advice is to select those QSOs in the Log Page DIsplay, and then on the Main window's QSL tab,
1. set the "QSL Via" panel to LoTW
2. click the "Update from LoTW" button
+ This will take longer to run than using the "Advanced Sorts, Filters, and Modifiers" window's "Modify QSOs" panel to 'U', but will produce a more accurate result.