14.4 "...your fifth dimension ..."

[unity100]

what is the best way to understand this phrasing?

Therefore, this was not pursued further. There was a landing approximately three oh oh oh, three thousand [3,000], of your years ago also in your South America, as you call it. There were a few attempts to aid your peoples approximately two three oh oh [2,300] years ago, this in the area of Egypt.

The remaining part of the cycle, we have never been gone from your fifth dimension and have been working in this last minor cycle to prepare for harvest.

is that the 5th subdensity of 3d, an inner plane?

That seems to be the 5th dimension in the time/space (astral) plane of this planet.