My feedback so far with a Fairphone 4 with 6 GB RAM and 128 GB internal memory and an MicroSD card for additional external storage:
Update went smoothly, everything works so far. 
Open Camera is able to use both back cameras by switching between them with the original Camera API as well as with Camera2 API. However with Camera2 API are 3 cameras reported: Camera ID 0, 2 and 3 where 0 and 3 are the same camera and 2 is the wide angle one. With the orignal Camera API only ID 0 and 2 are reported.
I can not test aptX right now, maybe I’ll post an about this later when I have access to a headset with aptX available.
Edit: aptX still does not work (Pioneer SE-MS7BT).