Going to fourth density? Or fifth?

[zenmaster]

No new 3D natives are born into 3D.

So then 3D ends when the last 3D native dies, but there is otherwise a total continuity of experience?

No, 3D doesn't end when the last 3D native dies.

There would be more transparency in thought (motives, desires, etc), for example.

What do you suppose will be the effects on 3D bodies?

Same effects you'd get from anything stirring the unconscious. Coping behavior and/or seizing the new opportunities now seen in a different light.

What makes something ironic? Why something is aesthetically pleasing or fashionable? What makes the ego feel safe and not safe?

What do these have to do with the planetary mind?

They are among the pattens the inhabitants have created as sub-sub-logos.

Sure they can, after 4D sphere is fully formed due to use by inhabitants. It's in an entirely different dimension.

So 4D instreaming begins shortly.

4D instreaming began awhile back. The full 4D streaming begins shortly.

Use of 4D catalyst by 3D/4D hybrids literally forms the 4D sphere during the "transition period" which is variable dependent upon how efficiently the catalyst is used. Meanwhile, 3D entities live out their lives and upon death await the 4D sphere to be completed, or are transferred to another 3D sphere.

Upon death, if they are harvested 4D positive. That is, grounded in that vibration. They don't wait for the 4D sphere to be completed.

What determines when 4D becomes inhabitable?

4D is inhabitable now here. It's just shared with 3D, hence the need for the dual-activation.