My
boat is
cutter rigged, this isn't quite the same as a staysail rigged
sloop. Since my staysail is club footed, it's self tacking but the yankee headsail is not. When I require or desire self tacking I just use the staysail and roll up the yankee.
As far as heaving to, my full
keel cutter will heave to with just the main sheeted in flat and a touch of
helm. I don't have to back a
head sail. As far as downwind is concerned, I can either fly the yankee or the staysail but would not try to fly both unless conditions were such that I could fly both wing and wing. In that situation it would probably mean the main was down.
I do like cutters,
Rich
Edit: I'm not really sure what you are referring to as a "spring loaded" boom.