Tina wrote:

Bertie, MX may not be overqualified as ballast. If, for example, I was
PIC (about 130 pounds) with a center of gravity (watch it now, if you
comment on the location of my center of gravity) 18 inches to the left
of centerline, a 260 pound ballast sitting in the back 9 inches to
the right of center would bring things into left and right balance.
There should be enough trim for fore and aft balance. You might assume
I would not invite ballast to sit in front.

Not only that, the last thing you want
is the ballast to move around and make
a mess. Since one of the reasons MX gives
for not flying is no bathroom, I think he
would be unsuitable for ballast, at least
in my plane.