k and b outboard
You are having an unusual amount of breakage. I've only had one break on my 3.5 tunnel and oddly enough, a friend was at the same race and broke one also that day. It's a good thing that I had 2 spares. I have replaced them when they do look like they are getting in bad shape.
I have always given all of my boats a flat level toss into the water. Number one reason is for less shock to the driveline and #2, they'll have less of a tendency to flip over backwards, not a good thing to do at a race.
Watch the RPM's so that it is not too high, flipping is one sure sign that of that.
You won't be able to get an X442 under the cavitation plate unless it is cut down. I ran mostly X437's and X438's on mine.
At what end are they breaking at? Tear it down to look for wear there that might be breaking the cables.