My mast is home made, got an extrusion with a different profile, so instead of buying the mast base and adapting it, I just went to a workshop and made one. It´s basically a plate with a solid cilinder with a half-sphere hollow on it, where the ball fits.

I always use a line, as a safety measure. Raising the mast is not a problem, the crew is usually enough help to get the initial angle, otherwise I use the trailer´s mast support (though a couple more degrees would be better..). But when lowering the mast, for some reason it comes out of the mast step easier.
I prefer not having anyobody restraining the mast base, I´d rather protect their lives and let the line do the work.