There's also something to say about 'parsec' ratios where the 'natural or regular' limit can't deploy more than 3 or 4 systems (i think) given the multiple setting options also allow for some sort of a maximum amount of available planets.
The size of a map may raise the bar on distribution but it never seem to overload such limits beyond parsable numbers by the engine.
Even the corner(s) or edge syndrome bothered me for awhile until i finally realized that it's not in the HOW things are spread but where exactly and as a result, within a relatively fixed pattern.
I prefer a swift 'low count' Medium map to everything above & below for more reasons than i could develop here but let's just say than no matter how epic or highly macro-managed my games get... the result is always the same; fun as i define it or want it by options.