I remember lifting engines like a champ and thinking about a better system of doing it until I switched to an electric outboard engine.
These days, I'm using the ePropulsion Spirit. I can carry it one handed. The battery gets clicked in once the engine's been mounted. Bonus: the battery floats in case it drops into the water.
Electric engines are not suitable for all use cases, I know. But I'm bringing up for inspiration, maybe you didn't have it on the radar.