Grouch.

When running a Staysail with a Jib, the Jib is not self-tending. The
staysail is the self-tending sail.

The Jib is flown from the head stay and the Staysail is flown on a inner
stay. This inner stay is shorter and the sail is shorter ( A staysail)
This is the sail that is often set self-tending. The tack of this sail
is located back from the stem and is usually set to make the inner stay
parallel to the forestay. That sets the peak of the stay at the location
on the mast at about the spreader, at the location of the lower shrouds.
This is to keep the Mast in Rig. If it creates unwanted Mast bend it
will require back stays. A PITA!!

A Jib can be flown and tacked thru the space between the head stay and
the Jack stay ( Staysail) Just have to run the Jib sheet forward of the
inner stay. Make sure you let enough sheet out when tacking and head off
enough for the wind to blow the sail thru or have some one there to hand
it thru.

Mooron says you don't fly the two together but that isn't true. Some
people can sail with the staysail working in the slot and get a gain
from it. I'm not one of them. I've never been able to keep the air flow
clean with a sail in the slot.

That is the big reason I sail a Sloop rather than a Cutter.

Ole Thom