If you use stall light both slats will come out, and also make no flight model difference.
One of the problems in real life when close to stalling in a turn, one wing slat would often pop out first due to that wing stalling first, then as the wing recovered and the slat popped in the other slat would come out as that wing was stalling - thus causing an oscillation, can't be done currently.


Regards,

Polovski,
OBD Software, developers of immersive flight sims;
Wings Over Flanders Fields and Wings Over The Reich
http://www.overflandersfields.com
http://www.wingsoverthereich.com