This map is getting old, but it's a good way to get an overview of where most of the surface stuff is at:
https://factabulous.github.io/CanonnED3D-Map/Source/poi-data.html
(flick the categories on and off and they're easier to see). Some things are more regional than others.
Penduncle trees are only seen where I don't think there has been that much traffic, whereas Lagrange clouds are mainly found along the path the Colonia (though it cuts off before getting there). This implies that Lagrange clouds are probably in more places, but Penduncle are restricted in their range.
Crystalline shards and Gyre Trees have only been found in the outer areas, Sinuous Tubers only in the centre. Anemones are all over (I left out Bark Mounds as they're also pretty ubiquitous).
So to answer the OP - yes there is stuff at the edge, but the edge is larger than the centre, and less travelled, so stuff may well take longer to find.