Is there a repository that should be 'preferred' for specific approach plates? Since people may have particular questions about one or another is there some sort of macro that can be set up?
I'm guessing you're thinking mainly of the US here? In theory the definitive reference for plates should be the FAA site because a) it's the FAA and b) it's free and public (unlike Jeppesen).
Interestingly, one question already found a difference between those two sources, but I think the FAA plates could still be considered the standard reference for general approach plate questions here. Outside the US the plates may or may not be available freely on line (I know in some countries you have - or had - to pay for them).
As for a 'macro' I'm not really sure what you're thinking of. Something like the chat bot macros to quickly look up or link to a specific approach? I'll have to defer to more knowledgeable people on that one.