Can't remember what kind of boat but i remember one builder/rigger who
deliberately cut the bottom of his mast tubes a liitle on the bias so
that the bottom panel of the mast was encouraged to bow forward under
compression.

Robert or Karen Swarts wrote:

I have unstepped the mast on my Coronado 25 and noticed that the mast foot
is flat in the fore and aft direction, but the tabernacle is stepped down
about 1/16" at the middle of the footprint of the foot. Anyone know why this
is? Was there originally a spacer of
some sort between the forward bottom of the foot and the tabernacle? Any
suggestions would be welcome.

Bob Swarts