@patricksh@mas.to for Linux, do check #SailfishOS, imho the most mature option. Jolla now sells hardware with (would recommend that), it can also be bought and installed on select phone (some Sony Xperias), and there is a community edition. (my daily driver is a Xperia 10iii). Tiny tablet combo: that's the way several Linux phone are setup - the phone part is an isolated USB modem. (am typing this reply literally on such tiny tablet: a PinePhone Pro running a community edition of SailfishOS)