Brew cask install java6 – Cannot install on volume / because it is disabled – MacOS 10.15 beta

I've un/reinstalled brew,
turned off macOS Gatekeeper,
csrutil is disabled,
and a bunch of other things but brew cask install java6 always results in this:

> $ brew cask install java6                                        ⬡ 8.11.4 [±OLYM-152-optimizely-web-per-banner ✓]
==> Satisfying dependencies
==> Downloading https://support.apple.com/downloads/DL1572/en_US/javaforosx.dmg
Already downloaded: /Users/mmooring/Library/Caches/Homebrew/downloads/ef0dff3db9496248774373eb3eba27a50a91e83edda3fe32d2197db15a5ffc69--javaforosx.dmg
==> Verifying SHA-256 checksum for Cask 'java6'.
==> Installing Cask java6
==> Running installer for java6; your password may be necessary.
==> Package installers may write to any location; options such as --appdir are ignored.
installer: Cannot install on volume / because it is disabled.
installer: A newer version of this package is already installed.
==> Purging files for version 1.6.0_65-b14-468 of Cask java6
Error: Failure while executing; `/usr/bin/sudo -E -- env LOGNAME=mmooring USER=mmooring USERNAME=mmooring /usr/sbin/installer -pkg /usr/local/Caskroom/java6/1.6.0_65-b14-468/JavaForOSX.pkg -target /` exited with 1. Here's the output:
installer: Cannot install on volume / because it is disabled.
installer: A newer version of this package is already installed.
Follow the instructions here:
  https://github.com/Homebrew/homebrew-cask#reporting-bugs
/usr/local/Homebrew/Library/Homebrew/system_command.rb:111:in `assert_success'
/usr/local/Homebrew/Library/Homebrew/system_command.rb:52:in `run!'
/usr/local/Homebrew/Library/Homebrew/system_command.rb:29:in `run'
/usr/local/Homebrew/Library/Homebrew/system_command.rb:33:in `run!'
/usr/local/Homebrew/Library/Homebrew/cask/artifact/pkg.rb:59:in `block in run_installer'
/usr/local/Homebrew/Library/Homebrew/cask/artifact/pkg.rb:65:in `with_choices_file'
/usr/local/Homebrew/Library/Homebrew/cask/artifact/pkg.rb:52:in `run_installer'
/usr/local/Homebrew/Library/Homebrew/cask/artifact/pkg.rb:34:in `install_phase'
/usr/local/Homebrew/Library/Homebrew/cask/installer.rb:214:in `block in install_artifacts'
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/set.rb:777:in `each'
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/set.rb:777:in `each'
/usr/local/Homebrew/Library/Homebrew/cask/installer.rb:205:in `install_artifacts'
/usr/local/Homebrew/Library/Homebrew/cask/installer.rb:103:in `install'
/usr/local/Homebrew/Library/Homebrew/cask/cmd/install.rb:23:in `block in run'
/usr/local/Homebrew/Library/Homebrew/cask/cmd/install.rb:16:in `each'
/usr/local/Homebrew/Library/Homebrew/cask/cmd/install.rb:16:in `run'
/usr/local/Homebrew/Library/Homebrew/cask/cmd/abstract_command.rb:36:in `run'
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:92:in `run_command'
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:158:in `run'
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:123:in `run'
/usr/local/Homebrew/Library/Homebrew/cmd/cask.rb:9:in `cask'
/usr/local/Homebrew/Library/Homebrew/brew.rb:102:in `<main>'

I've tried and answers from this Apple StackExchange Question:
How to run an app that require Java SDK on macOS Catalina 10.15?

Any help will be greatly appreciated as I've been blocked now for a few days. ??‍♂️