This one took some time to figure out. It seems bluetoothd does not use the DisablePlugin= setting in /etc/bluetooth/main.conf. To change the bluetooth name, follow the next steps.

• Change the Name and other settings as you wish in /etc/bluetooth/main.conf.
• Create a new environment file /etc/sysconfig/bluetoothd and add options. The noplugin option lets you disable the hostname plugin. That plugin will reset the bluetooth name to the hostname regardless of the configured Name.

  OPTIONS=--noplugin=hostname

• Edit the bluetooth service and add the lines below. It will create an override.conf file for the service:

  systemctl edit bluetooth
  
  [Service]
  EnvironmentFile=/etc/sysconfig/bluetoothd
  ExecStart=
  ExecStart=/usr/libexec/bluetooth/bluetoothd ${OPTIONS}

• Reload the systemd config:

  systemctl daemon-reload

• Restart the bluetooth service:

  systemctl restart bluetooth

• The daemon should be running with the options you've configured:

  pgrep -a bluetooth
  5494 /usr/libexec/bluetooth/bluetoothd --noplugin=hostname

• Test with:

  bt-adapter -i