There's another short update on the EPI website. It just says:
!! YAY - EARLY JANUARY 2020:
ENDURANCE TESTING HAS BEGUN ON THE PRODUCTION VERSION OF THE ENGINE
http://www.epi-eng.com/aircraft_engine_products/aircooled_4-cyl_aircraft_engine.htm
!! YAY - EARLY JANUARY 2020:
ENDURANCE TESTING HAS BEGUN ON THE PRODUCTION VERSION OF THE ENGINE
http://www.epi-eng.com/aircraft_engine_products/aircooled_4-cyl_aircraft_engine.htm