The Pro1 X is a collaboration between F(x)tec and XDA Developers with native support for both LineageOS and Ubuntu Touch. The price is high for outdated hardware and long lead-times, though.
https://www.notebookcheck.net/Pro1-X-XDA-Developers-collaborates-to-create-the-world-s-first-Lineage-OS-and-Ubuntu-Touch-smartphone.499565.0.html