That is a good question, how large are the compression forces. I know the current mastfeet are made in silicone bronze and steel..
Shall we see. 400Kgs of sheet tension on the leech and perhaps 180Kgs of crew trapeezeing 2.5 meters from the centerline. Add a fudge factor, dynamic loads etc and I suppose the mastfoot easily have to be able to handle loads up to two tons? Just a guesstimate, I hope those who have done the calculations will chime in.