Hi @elliot,
Please note: we’ve decided it’s best to focus our upgradeability efforts on the Upgrades Plugins exclusively, and have halted development on the OpenZeppelin CLI. For details see:
Building for interoperability: why we’re focusing on Upgrades Plugins
I had a quick play with the Truffle configuration but didn’t get very far unfortunately.
I was curious as why you wanted to use the OpenZeppelin CLI for compiling in a truffle project?