I had Unihertz Jelly Star for 1.5 years until recently. I loved how small it was but the first thing I did when I bought it was flashing it with LineageOS because I did not want to have the Chinese Android on it. That, unfortunately, meant that each time I wanted to update, I had to wipe the phone and flash it again with new version of LineageOS, and I got tired of that. So I went for Motorola Razr 50 and I will never return to Unihertz again.

I am using Unihertz Jelly Star for more than a year now with custom LineageOS ROM. Works well with it. I used this guide to flash it: https://www.reddit.com/r/unihertz/comments/16sviga/unihertz_jelly_star_running_great_with_lineageos/