EXS 24 Logic Sampler Users Group

I'm just getting into making a new drum library for the EXS24II (in Logic Pro 7), and 
I'm a bit confused about what parameters are saved where.  

For example, the factory 'instruments' displayed in the EXS plugin editor (the 
instrument drop down above the cutoff knob), but those same factory 'instruments' do 
not have 'plugin' patches associated with them (in the drop down below the 'bypass' 
button on the EXS24 plugin).  So if I do a search in the finder for the EXS factory 
instrument "Helicopter Action", all I find is "Helicopter Action.exs".

However, if I load several of the factory instruments, I notice that they have different 
'plugin' settings (i.e. envelope, cutoff, modulation, etc), but if I search for the names 
of those instruments in the finder, I only find *.exs files, no *.pst files, which are 
supposed to be the plugin settings for the EXS24.  So it seems that the factory 
patches are getting different plugin settings from somewhere, but they don't have 
*pst patches associated with them.

Are plugin settings saved in instruments (*.exs files) ??  If so, how come when I create 
a new instrument and save it, it doesn't save the plugin settings I was using at the 
time I create the instrument ??  More importantly, how do I manage plugin settings in 
general, with new patches I create ?

If somebody could enlighten me, I'd greatly appreciate it.  Thanks.

Paul