Abrupt vs gradual harvest

[Tenet Nosce]

That portion of the quote does not conflict (or add to) my viewpoint. It is simply describing why all are harvested regardless of progress.

You said:

It even explains why. The planet ceases being useful for that density.

The actual quote says:

begins to cease being useful for the lower levels of vibration within that density.

Ceasing and beginning to cease are two different things. That the ceasing has a beginning implies that it is gradual. If it were abrupt, it wouldn't make sense to speak of the ceasing as having a "beginning" or "ending" as it would all happen at once.