ok i'm in the process of going with option 2 and i'm getting a warning "DLL for US99820a is invalid. Please install valid DLL package (*.msi) for the model" .....?
---------- Post added at 09:02 PM ---------- Previous post was at 08:49 PM ----------
LG UP (non developer) recognizes it but of course there i only have 4 processes to choose from - refurbish, upgrade, FOTA upgrade and phonesetting.....
It doesn't look like you were using uppercut, but just in case you were, it doesn't work with Windows 10 because of how the latter permissions Program Files folders. You don't end up having correct DLL inside LG UP folder structure. If you just use LG UP and manually copy US998 dll in there everything should work.
---------- Post added at 01:10 PM ---------- Previous post was at 01:07 PM ----------
It's not entirely compatible with T-Mobile. You will lose WiFi calling and VoLTE. I also had issues with SMS with two separate clean installs. Additionally, if you look through the Boombox thread, you'll see Verizon and Sprint users having issues.