How can I relocate or disable the VirtualBox logfile when starting a vm from Vagrant?

I managed to change the log file location as per this post. To change the log file location to a folder called /temp relative to my Vagrantfile, I added this to the Vagrantfile (inside the Vagrant.configure(2) do |config| - section):

config.vm.provider "virtualbox" do |vb|
  vb.customize [
    "modifyvm", :id, "--uartmode1", "file",
    File.join(Dir.pwd, "temp/ubuntu-xenial-16.04-cloudimg-console.log")
  ]
end

This seems to override the current location settings. The temp-folder must already be present.

To completely disable the log file output, follow the recipe from the above link:

config.vm.provider "virtualbox" do |vb|
  vb.customize [ "modifyvm", :id, "--uartmode1", "disconnected" ]
end