The game does not enforce it but it is design that trade nodes should never break areas. In cases where they do that's something we'd classify as a bug and it should be reported.
Regions are another matter, we would not want to be restricted by those for trade nodes as that would create some pretty silly situations and prevent us from being flexible for history and gameplay when creating them just to have a neater database
All of the above is also true for trade company regions and colonial regions, they should not break areas but do not respect region boundaries.
Areas, regions and subcontinents/super regions already are defined as groups of eachother and so will be consistent. We aim to not have continents breaking areas/states in the future but we likely won't restrict regions to continent boundaries for similar reasons as above
Edit: defining trade modes as groups of areas directly is something I'd like to see though but I have a feeling the mod community would not be crazy about being restricted like that.
Regions are another matter, we would not want to be restricted by those for trade nodes as that would create some pretty silly situations and prevent us from being flexible for history and gameplay when creating them just to have a neater database
All of the above is also true for trade company regions and colonial regions, they should not break areas but do not respect region boundaries.
Areas, regions and subcontinents/super regions already are defined as groups of eachother and so will be consistent. We aim to not have continents breaking areas/states in the future but we likely won't restrict regions to continent boundaries for similar reasons as above
Edit: defining trade modes as groups of areas directly is something I'd like to see though but I have a feeling the mod community would not be crazy about being restricted like that.