This "skip" is not useful, at least for now, because it doesn't actually skip to c14. it loads parts of c14, but the game still thinks you're in whatever chapter you started at. after you complete this "fake c14", you go to next chapter. So if you skip in c11, it goes to c12. But this next chapter is also glitched, and game loads another "fake c14". If you somehow complete this one as well, it then loads the next one (c13 in this example), and this one will be loaded properly. So basically you're doing repeats of c14 to skip one chapter, and only on specific points it's even possible to complete multiple "fake c14's".
Here is the only way I found to use the skip while still completing the game: Skip in C11 end, after dropping Joe off. go outside Marty's to hit a level end trigger (hit trigger on foot so it doesn't bug out). Game loads "fake C14" (instead of c12). Now you'll need to get 27,5k cash, then skip and go to Greco to get another 27,5k. Go to bruno, C13 starts. get 27,5k cash again, then finish C13 normally. C14 starts. Go to Joe's, then Mona Lisa, Greco, Bruno, and C15 as normal. This method only skips C12, and needs you to grind 27,5k cash twice. Grinding cash is very slow. the dock export is the best way, but the crane animation takes around 70 seconds between accepting cars, and even the best cars that spawn nearby only give ~2,5k.
joe gives you double amount of money at el greco in definitive, so this can remove money grinding. if you do skip at c11 end then go to marty (hit the trigger inside the car, then reload checkpoint to remove buggy shit. this allows to skip joes phone call and thus not to acquire him as a companion while also it removes injured joe from the previous chapter from companions list) then skip, greco, bruno, c13-15 as normal, you can save whopping ~10 seconds (in DE!) compared to doing things as usual. but at least no need to deal with the fence skip in c12. apart from doing the same thing, but at c12 start instead of c11 end, this is seemingly the only one working application
