Having now played around for over a week with my Pi 4B (4Gb, latest Rasbpian Buster) I've fixed most of the critical things that were problematic to me, but I do still observe a few weird things:
1) I run a small touchscreen case and a larger HDMI screen for less nomad times. Let's say I have both screens on with both desktops set up: touchscreen rotated to landscape, HDMI screen at 1920x1080 that doesn't overlap with the touchscreen.
- If I turn off the HDMI screen and plug out both power and HDMI, the touchscreen continues to chug along and works fine on reboot.
- However, if I turn off the HDMI screen but fail to unplug HDMI (whether the power plug is still in or not!), then upon reboot the touchscreen configuration kind of reverts to default: portrait orientation, and the settings for the HDMI screen are lost (resolution and placement of the workspace)
Now that I know it's all about the HDMI cable it's not a big issue, but strange nonetheless.
2) My Bluetooth works, but is capricious. If I just connect my earphones (Anker SoundBuds Slim+), the connection drops after what seems to be a fixed delay of ~30 seconds and immediately connects again. If I start a sound (e.g. youtube video), I will not hear anything until the next time the connection automatically reconnects. After that, the connection is rock stable for as long as the sound keeps playing. I've listened to a Youtube playlist for basically all day with no issues. On occasion after a reboot, the earphones still seem to connect but steadfastly refuse to play any sound. The only fix I have is to turn them off, reboot, then turn them on again and let them auto-connect.
3) This is more of a question. I've made a handful of adjustments to make the Pi work the way I want it to - changes to config.txt, LXDE panels, a few additional modules etc. When the next Buster update comes, will all of these revert to default? If so, should I create a script that automatically performs these changes ?