they list the compatible phones but the one i intend to get has at least 3 or 4 different configurations, ranging from 4-8GB RAM. and now i wonder if that’s going to influence the performance? i mean sure it does at some point but i am talking about the baseline performance not the one with a dozen apps running.
https://devices.ubuntu-touch.io/
https://www.gsmarena.com/xiaomi_redmi_note_9_pro-10217.php
16.04 xenial ran really well with even 2gb (arm64), i believe 4gb should be plenty even for latest ver