Great News! PACT wallet for recent macOS versions is available for download:

HIGH SIERRA: https://github.com/pact-works/pactcoin/releases/download/v1.1.2/PACT-HighSierra.dmg
MOJAVE: https://github.com/pact-works/pactcoin/releases/download/v1.1.2/PACT-Mojave.dmg