Looks like although I can install an rpm within a toolbox container, I can't run x11 applications from it?
wget 'https://go.microsoft.com/fwlink/?LinkID=760867' -O ~/Downloads/code.rpm
toolbox -y create --container vscode
toolbox enter --container vscode
sudo dnf install -y ~/Downloads/code.rpm
⬢[user@toolbox ~]$ code
/usr/share/code/bin/../code: error while loading shared libraries: libX11-xcb.so.1: cannot open shared object file: No such file or directory