Fairphone | FP3+ | FP3 | previously on e-2.5-t-20241111446827-community-FP3 | not rooted
I upgraded to 2.6.3-U (Android 14) using ADB Sideload. The Recovery reported the installation as complete when progress on the computer side was still stuck/shown at just 47%. It took like 2-3 minutes to boot the FP3+ (the little ball under the e symbol was bouncing longer than usually). Initial impression is a bit laggy, but I’ll see if this levels out after a while. The two active apps (Desktop clock and VLC 3.5.7) initially gave incompatibility prompts referring to the new Android 14, but still work.
Other Fairphoners, please note: 2.6.3 is available for the FP3, FP4 and FP5 only as a community build right now (official build not yet) and 
both in a T (Android 13) and a U (Android 14) version for the FP3 and FP5. For the FP4 there is only the U version. From all I know you will get the T version if you update OTA. Feel free to check what’s online for you:
/e/OS community FP3 download or /e/OS official FP3 download
/e/OS community FP4 download or /e/OS official FP4 download
/e/OS community FP5 download or /e/OS official FP5 download
You might need to click on the “Android T(13)” line to see the T builds.
P.S.: As @piero and @AnotherElk educated me a while ago (and as my own installation confirmed again now 
), for ADB sideload you need to alter the download URL from https://ota.ecloud.global/community/FP3/IMG-e-2.6.3... to something like https://ota.ecloud.global/community/FP3/e-2.6.3... (so you just remove the IMG- part – and alter the parts before depending on your Fairphone model).