Reason lunges are not often in exercise selection?

I have several BBM templates and noticed that lunges are not listed as an option under the squat or squat supplement exercise selection. I know we are not supposed to feel strictly limited by the exercise list.

Is there a reason you disfavor lunges or is this just a cant list everything situation?

Lunges are perfectly fine, especially in contexts where we list split squats.

This might be a dumb question but Hypertrophy I lists split squats and lunges as an option for the leg accessory slots. What exactly is the difference?

I’m assuming both are weighted, if possible. Is the difference that the lunge returns to a full upright position between reps where as in the split squat your feet remain split between reps?