My stable configuration file for Volumio looks like this now:

  1. Basics:

    initramfs volumio.initrd
    gpu_mem=16
    max_usb_current=1
    disable_splash=1
    
  2. Sound card:

    dtparam=audio=on
    dtparam=i2c_arm=on
    dtoverlay=hifiberry-dacplus
    dtoverlay=lirc-rpi:gpio_in_pin=26
    
  3. WaveShare screen:

    max_usb_current=1
    hdmi_group=2
    hdmi_mode=87
    hdmi_cvt 1024 600 60 6 0 0 0
    hdmi_drive=1
    
  4. Network:

    auto lo
    iface lo inet loopback
    
    allow-hotplug eth0
    iface eth0 inet dhcp
    
    allow-hotplug wlan0
    iface wlan0 inet manual
        wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
        post-up ifdown eth0
    iface default inet dhcp
    

The only more convoluted configuration is the networking, which allows me to connect to my wireless network. Once the setup will be stabilised, I will be able to connect it via ethernet, making the whole last section obsolete.

And the wpa_supplicant.conf file looks like:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
  ssid="ssid"
  psk="passphrase"
  id_str="Home"
  proto=RSN
  key_mgmt=WPA-PSK
  pairwise=CCMP
}

HTH,