@RoyD the current effort to port Halium / UT to BQ devices are only on these models, at least for now: https://github.com/Halium/projectmanagement/issues?utf8=✓&q=is%3Aissue+is%3Aopen+bq
Maybe you can ask https://aquaris-dev.org/ if there's any chance to port LineageOS to U2 🙂