I run a lot of RWG 8k maps with default settings and my modlet -- because I'm testing my modlet. You get pretty close to everything with an 8k map. Off the top of my head, places where you may not see everything are:
- Industrial POIs. The district is small and competitive.
- Commercial POIs. The larger POIs sometimes get squeezed out for density.
- Downtown POIs. TFP is battling density here and flooding the place with filler POIs.
- Western Town POIs. There's not a lot of Tile variety because the towns are really small.
Conversely, areas you get lots of repetition:
- Wilderness.
- Rural POIs.
- Residential.
If you constrain your map to 4k you'll likely never see everything placed.