Obviously, Delta isn't going to pay much mind to a customer taking 16 flight a month for <$1500.
I don't think you'll do much better with any sort of negotiations. The best bet is to create an LLC and negotiate a small biz discount with a Delta sales rep. I was commuting *weekly* to LA for 6-8 months (from SEA) and our company deal got me 2-3% off the lowest available rate. It was roughly the same across all routes, including monthly paid business class to MNL.
Not the advice you are looking for, but I think this proposition of daily roundtrips would add up to a miserable lifestyle. Going out of LA is just no fun. Are you going to park a car there? The parking or rental shuttle experience is miserable. And Ubers to the terminal door will add up quickly.
If it were me, and extenuating circumstances required me in LA a lot, I'd look into getting an airbnb room (not even a full apartment, but a room) for something like Mon/Tue/Wed nights and commute Monday-Thursday. No doubt you can negotiate a rate with the owner that would be better than all of those flights... and you can keep your sanity. (And once you find a "regular" crash pad that suits you, the owner will give you a better deal and you can circumvent the platform.)
Not knowing about the extenuating circumstances, it isn't like you'd have much time in LA to tend to them in the hours between the back-to-back flights days.
Edited to add: You are a great candidate for
SurfAir. I would strongly consider that if in your shoes. I can introduce you to a founder if you hit me up with a PM.