Special weapons effect on units

[Q]

I made some strange observations in the combat simulator when using special damage type weapons against units:
- shield depleter seem to have no effect at all: no shield depletion occured.
- nullspace weapons and weapon damaging weapon seem to have no effect at all on weapon platforms.
- nullspace weapons seem to work correctely agains sats, but again weapon that damage only weapons seem to have no effect.

Anyone made similar observations?? Is this a bug or a feature???