If you have both been mono sailing your reaction times will easly be as fast as cat sailors. If you are used to flipping out sometimes in a dinghy the water will feel the same.
A very sensible thing to do is flip the boat near the beach and practice getting back on board.
If you are lifting going up wind actually going over takes a year. As a mono sailor you will find it a laugh. Last thing as you are standing on the side of the boat thinking..ooops, unhook.

Go out and just play. Lift it and take it up further and further each time. Get the boat so you are almost on your side and sitting on the outside of the boat. Just stay there almost not moving and high up and looking about. This type of play will make you feel safer and sail better. While you are up on that angle check the drop. More of a slide really. I used to dry roll a lot in monos so I do the same thing on a cat. Just drop down the outside onto the hull using the board as a grip.