Optimise your mods for vanilla AC? What for? Lazy? Why? I don't get your point, csp adds so many features I don't see why a modder should make worse mods when he can make better ones.
Also who said you need a million mods? You only need csp and setting it up takes five minutes top, I really don't understand what the issue is but you do you, just don't think anyone should do stuff for the base game when it's clearly obsolete just because you don't want to install "millions" of mods
No what I mean is the car mods should be optimized for the vanilla AC. If it looks good in vanilla AC, it can look even better with graphic mods. But let's say you have 2 graphic mods (2 configuration of CSP), and you make your car mod look good on one, it will not neccessarily look good on the other configuration, or in fact in vanilla AC. So while yes you can ofcourse add features like GPS and whatever CSP offers, but if the whole package doesn't work with just a vanilla AC or with other configurations, it doesn't really work good as a mod. Modding is about making your game look like how you want it to look, making a car mod dependent on CSP for example, will not enable you to have that car and not having CSP. Is that better explained?
CSP is just not enough, like you said you still need to set it up, which is a complete mess. You have such computer graphic definitions there that most people do not understand. And if you really want to make your AC look good, you first need CSP, then you need SOL, then you need a different version of SOL that enables time changing and weather changing, and then you have the ppfilters and let's not forget about the track light settings, or in fact it matters which version of the track you're choosing, since some don't support this and that feature and all of these mods have an insane amount of versions of it. It's just overcomplicated. I'm sure you can make your AC look good, but I cannot and will not spend hours on a game, just to set it up, or watch through 55000 YT tutorial videos which all start like: *super high pitched voice* "HEEEEEY MY BITCHES, don't forget to like and subscribe" and other nonsense like that.
Anyway I don't want to attack CSP, since it's an amazing mod that brings lights and nighttime to AC, but the one I do want to emphasize is don't make a mod dependent on anything else, unless it's an improvement of that other mod. So car mods should not be dependent on CSP.