like what? i can include something, but you have to know it's never going to be a dating sim.
Would it be possible to include a "real couples" mechanic where there's a scene chemistry bonus to a girl/guy shoothing with boy/friend girlfriend?
When the random "angry boyfriend" event triggers maybe spawns a male who is the model's perfect match (Both have high likeness for the other's looks). So highest possible likeness match and this also means they'll get pissy (be less happy) shooting with others. Maybe add an event where they get into fights causing damage (money loss, equipment, unavailability); security could play a factor.
I really like how the Add BF/GF is going, all it needs is for dates to lead to a scene. Dates could be used as a way to increase a girl's happiness; without drugging them up. For a bit extra could include gifts that increase happiness (jewellery store an option maybe?).
Like you alluded to it's not really a dating sim so I think just dates leading to a scene is enough for date roleplay. If MC/FC wanted to participate in a stable healthy realtionship, then they wouldn't be filiming themselves fucking strangers and posting it online for BF/GF to see.