On MTP media, there's android-file-transfer.

On the screen brightness, there's 'xbacklight', you might be able to set it ~/.fluxbox/autostart with a line like this
at the end:

xbacklight -set 40

The annoying screen brightness that does not detect lumina to reduce and do not fuck the eyes, I do not know how to make a script so that by default at system startup detects the brightness and lower it automatically.

The 2nd one you do only until you reboot.
btw, console-tdm is also an option if startx doesn't work or if you don't want it, for future reference.

1. Enumerate on your system which kind of possible sound-output is there. Therefore the question is relevant: Is this a real system or a virtualized solution?
2. Please remember that Hyperbola is mainly supporting sndio so you should verify if there is a generic sound-output given or you have a complex solution with more possible devices like HDMI-generated.
3. Verify that alsasound and sndiod are running at the default-level minimum for services with OpenRC.

All in all you need to find a solution here for your current hardware-setup as we have made the experience that finding here a concrete point won't fit the needs. I hope you understand that as this question is also no longer related towards problems with the x-server. Further reading for helping: https://forums.hyperbola.info/viewtopic.php?id=790

Note:
In view of the fact that there is no solution for this Xorg bug, it looks like I am going to reinstall the system from scratch.