There was a
complaint about the Hardlight malfunctioning never occurring. I wonder if there's a backwards logic check or something.
From what I can see, if I'm interpreting it right, the character must have a hardlight-enabled lower garment equipped and have the hardlight upgrade, and if it's the first time (where Aliss has never repaired it before), the hardlight malfunction should occur about 20 days or so since the upgrade--but only when the character is in a room where public masturbation is not prevented--at a 1 in 25 chance over time.
For the actual use of the upgrade, only a small handful of scenes actually use the upgrade, so it's not really something the player can adjust themselves. Scenes that use or acknowledge it are related to: Sellesy on Tavros, Shelly on Tavros, Syri (on M'henga?), the Myrellion bathhouse, Liliana on Myrellion, Mirrin on New Texas, and the brothel on Dhaal.
Hope this helps.