These are all of the steps worked out by jsm174, he gave me permission to post them here. I followed them and the installation works but all of this is way beyond my knowledge base.
# Enable 3D Acceleration:
sudo add-apt-repository ppa:liujianfeng1994/panfork-mesa
sudo add-apt-repository ppa:liujianfeng1994/rockchip-multimedia
sudo apt update
sudo apt dist-upgrade
sudo apt install mali-g610-firmware rockchip-multimedia-config
# Reboot
sudo reboot
# Install development tools
sudo apt-get -y install build-essential zlib1g-dev libncurses5-dev libgdbm-dev libnss3-dev libssl-dev libreadline-dev libffi-dev wget
# Install MPF dependencies
sudo apt-get -y install libsdl2-dev libsdl2-ttf-dev libsdl2-image-dev libsdl2-mixer-dev gstreamer1.0-plugins-base gstreamer1.0-plugins-base gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly libgstreamer1.0-dev libxine2-ffmpeg libsmpeg-dev libswscale-dev libavformat-dev libavcodec-dev libavdevice-dev libavfilter-dev libjpeg-dev libtiff5-dev libx11-dev libmtdev-dev libgl1-mesa-dev libgles2-mesa-dev pulseaudio lsb-release
# Download, compile, and install Python 3.9
wget
https://www.python.org/ftp/python/3.9.1/Python-3.9.1.tgztar -xf Python-3.9.1.tgz
cd Python-3.9.1
./configure --enable-optimizations
make -j 2
sudo make altinstall
# Install MPF
sudo pip3.9 install "mpf[all]" grpcio==1.36.0 grpcio-tools==1.36.0
sudo pip3.9 install "mpf-mc[all]"
........................................
# Install QT6 dependencies
(Adapted from
https://doc.qt.io/qt-6/linux-building.html and
https://www.ics.com/blog/how-build-qt-640-source-ubuntu-linux)
sudo apt install cmake bison build-essential clang flex gperf libatspi2.0-dev libbluetooth-dev libclang-dev libcups2-dev libdrm-dev libegl1-mesa-dev libfontconfig1-dev libfreetype6-dev libgstreamer1.0-dev libhunspell-dev libnss3-dev libopengl-dev libpulse-dev libssl-dev libts-dev libx11-dev libx11-xcb-dev libxcb-glx0-dev libxcb-icccm4-dev libxcb-image0-dev libxcb-keysyms1-dev libxcb-randr0-dev libxcb-render-util0-dev libxcb-shape0-dev libxcb-shm0-dev libxcb-sync-dev libxcb-util-dev libxcb-xfixes0-dev libxcb-xinerama0-dev libxcb-xkb-dev libxcb1-dev libxcomposite-dev libxcursor-dev libxdamage-dev libxext-dev libxfixes-dev libxi-dev libxkbcommon-dev libxkbcommon-x11-dev libxkbfile-dev libxrandr-dev libxrender-dev libxshmfence-dev libxshmfence1 llvm llvm-dev ninja-build nodejs python-is-python3 python3
# Install QT 6.4.2 (Takes about 1-2 hours)
wget
https://download.qt.io/official_releases/qt/6.4/6.4.2/single/qt-everywhere-src-6.4.2.tar.xztar xvf qt-everywhere-src-6.4.2.tar.xz
cd qt-everywhere-src-6.4.2
./configure -prefix /usr/local/Qt6
cmake --build . --parallel
sudo cmake --install .
# Upgrade PIP
sudo /usr/local/bin/python3.9 -m pip install --upgrade pip
# Prebuild PyQt6 (Required because PyQt6 is asking questions that can't be answered during pip3) (Takes about 1 hour)
sudo PATH=/usr/local/Qt6/bin:$PATH pip3.9 install PyQt6 --config-settings --confirm-license= --verbose
# Install MPF Monitor
sudo pip3.9 install "mpf-monitor[all]"