Hello. I love LSPDFR; it is the main reason that I bought GTA V. However, there are a few things I would love to see in this mod, perhaps even optionally if you thought they would be controversial.
I would love to see less predictable AI. I know that there are already chance attributes on things such as spawning a pursuit when pulling someone over to add a bit of variety, but it still seems as though replay-ability is declining. I think that it would be amazing to have a small chance, maybe 1% or 2%, of being shot at/attacked/knifed when approaching a vehicle or during/after pursuits. A chance of being shot at, attacked, knifed, or spawning a (foot) pursuit when doing a takedown or putting cuffs on a detained pedestrian would do wonders for the gameplay and immersion as well. This chance could be something potentially modifiable in an .ini or configuration GUI if that were a possibility, but if not, it would still be awesome to have some variety because it frankly can get quite boring and tedious to hold point a gun at someone and hold E and have that work 100% of the time. The feature of having more variety and less predictable AI was very prevalent in LCPDFR on GTA IV, and was, in my opinion, the best feature. I would absolutely love to see this get carried over to LSPDFR soon as well.
EDIT: Another suggestion, also present in LCPDFR and not LSPDFR, was the ability to toggle lethal force in pursuits. This could potentially stop AI helicopters from firing at suspects unlawfully, and allow officers to shoot at suspects who are driving extremely recklessly in order to bring the pursuit to a stop.
EDIT2: A configurable hardcore mode was also one I used in LCPDFR which was lost on GTA V. This would be an awesome addition on the realism front.