Try the 109k, it is the most squirly 109.
Just tried it, same variations in the testing, and could get no visual evidence or evidence of flight effects from asymmetrical deployment no matter how hard I tried. The airplane tends to drop a wing to whichever side when you whip into an accelerated stall in uncoordinated flight (except when you have the engine at WEP, then the airplane *really* does not want to roll right under any circumstances), but there is nothing even resembling the sort of un-commanded roll effect I would expect from uneven slat deployment when not stalled.
A time or two when I was visually inspecting the aircraft in external views the sound effect *sounded* like one was slamming closed after the other, but as the visual picture and flight effects did not agree with this conclusion, I assume its a sound thing and not related to flight modeling.
I also note that the slats are not found on the damage list for the 109 (Or any other aircraft IIRC) and thus presumably cannot be shot away or jammed.