UPDATE:
I’ve updated my remote pi, and in principle it still works. I just made a few adjustments to the install script. I added instructions to update platformio and pip python packages, so the same script can be used to update the installation. pip upgrade is required to make sure requirements can be compiled successfully.
# update system
sudo apt update
sudo apt upgrade -y
# install required packages
sudo apt install python3-pip libffi-dev libssl-dev
# install platformio
sudo pip3 install -U platformio pip
# install required libraries for the remote agent
pio remote agent