Currently, when a Nectere portal is generated on the Non-Nectere side, it must be generated through BlockEntity because portal placement requires knowledge of biomes in the Nectere dimension. However, when portals generate on the Nectere side, only a simple check is performed to see if the portal is generating in a location linked to a valid Non-Nectere location. This check is done using the non-nectere world's biome generator and much care must be taken not to actually load any non-nectere world chunks, as this would cause a threading deadlock.

It would most likely be best to generate nectere portals on both sides using the portal spawner block entities. It might make sense for these to place 'structures' in the world when they generate the nectere portals.