Hello,
Upgrade via TWRP directly.
EDIT: But before upgrading, you should wait some feedbacks if this "Stable" ROM is passing SafetyNet or not...
EDIT BIS: Flash latest TWRP version too => https://androidfilehost.com/?fid=2188818919693777989
All good so far, will see in the following days if it's a keeper.
Lack of L1 bugs me a little, but this is from before. I might've screwed up by formatting system a year ago.