Hello, I just installed the ROM of LineageOS 14.1 (Android Nougat 7.1.2) on my T560 this week and it runs smooth without any big issue. I confirm the known bug (when the tablet if off, no battery loading indicator). It detects 1,4 Go of Ram, uses 744 Mo and have 706 Mo of free available Ram (744+706 = 1,4Go of Ram, it's correct).
I've only installed Open Gapps
pico because the tablet is quite old and need to be fast before to be modern in my opinion, so Android System WebView is the native one (AOSP), there is no unnecessary backend process than the apps I manually installed (Chrome, Gmail, Youtube, Gboard).
VOL- + HOME + POWER keys works fine on my tablet. Files are always on my SD Card but I don't know if I can delete them.
I would just notice @
SeeDoubleYous that I did not mention after TWRP installation, the shortcut is not
VOL- + HOME + POWER but
VOL+ + HOME + POWER