The main problem with FOSS Android seems to be that your device has to be actually supported due to the myriad of cpu, graphics etc. combinations. I looked shortly for a tablet of mine which is completely workable but hangs at Android 4.2 - unfortunately there doesn't seem to be a CyanogenMod variant for it (so, probably no Lineageos either). The update story of Android devices is really sad ..
Thanks for the hint, will look into it. My current tablet is an old Huawei (Mediapad T1 10/T1-A21L). It was part of a promo action and does what I want (I mainly use it was PDF reader), but Android 4.2 gets old and security doesn't get better, so maybe time for an upgrade and this time something LineageOS supports.
