Can you make one to show how my max-prop made my boat go astern with the transmission in forward this summer ?
No video/illustrative skills have I, but back when we were using a feathering prop for a decade, that same thing did happen to me. Scary.

I was backing out of a slip in a tight fairway, with a cross wind. With the sterns of the boats on the other side of me coming up quickly I put the transmission in forward.... and hit the throttle and went back more! Excitement ensued. realizing that the blades were still reversed on our prop, I repeated the shift/thottle/prayer routine and the boat leaped forward just-in-time.
Later I re-greased it with the recommended grease product which is less viscous than the usual marine green grease. I was advised by the vendor that our cold water in the Columbia River makes the lube viscosity very important. The guys at PYI know the right grease product; I could not find it locally at the usual stores -- they sold me some at a reasonable price. Lubriplate 130 AA .
Yachting can sometimes be ... exciting...