Is emptiness conventionally non-empty? Is emptiness conventionally / provisionally non-empty?  Please include reference to whose perspective you are replying from.

By empty I mean non-substantial, how dharmas are constantly arising and perishing, and nothing is the same from moment to moment, but in flux.
By conventionally I mean in the sense that enlightened beings can use &quot;I&quot; to refer to themselves, even though they ultimately lack any self identity at all or sense of &quot;me and mine&quot;.
BY non-empty I mean permanent.

I know that there are debates about the identity of the conventional truth and emptiness, and Nagarjuna said that emptiness is empty.
I read Gelek Rimpoche - Geluk lama - say that he'd &quot;love to say emptiness is impermanent, but emptiness is meant to be permanent&quot;, because it is uncompounded and uncreated. And a translation of The Great Prajna Paramita Sutra, saying it is neither permanent nor impermanent.
Personally, I would guess that it is identical to impermanent dharmas (there's discussion about that in early ch'an, seemingly explained by Zongmi), not permanent, and yet does not arise or cease, is not impermanent.
Then it's both empty and non-empty: changing in accordance with conditions, but not dependent on any individual conditioned thing. Arguably, I am rich independent of any one of my financial investments, even-though it changes with all of them. Not a great analogy, but I can't think of anything else that could be &quot;permanent&quot;.
I'm still learning but I'll add some references which might help you to contemplate on this.
Is emptiness conventionally non-empty?
In MN121, The Buddha explains the different levels of emptiness based on 'the perception that are not present and  which are present'.
But when through such emptiness approach one attains awareness-release i.e. here cessation of craving phenomena and aggregates then it is now better to describe it as cessation (unbinding) to avoid confusion. -- (from my viewpoint)

And what is the path that leads to the unconditioned? Emptiness immersion; signless immersion; undirected immersion. …” [SN43.4]

Also in MN1, It is mentioned that how a trainee or Arahat understands Nibbana but Tathgata doesn't even grasp to Nibbana after he understood it.
BEGINNER:

He perceives Unbinding as Unbinding. Perceiving Unbinding as Unbinding, he conceives things about Unbinding, he conceives things in Unbinding, he conceives things coming out of Unbinding, he conceives Unbinding as 'mine,' he delights in Unbinding. Why is that? Because he has not comprehended it, I tell you.

TATHAGATA:

&quot;He directly knows Unbinding as Unbinding. Directly knowing Unbinding as Unbinding, he does not conceive things about Unbinding, does not conceive things in Unbinding, does not conceive things coming out of Unbinding, does not conceive Unbinding as 'mine,' does not delight in Unbinding. Why is that? Because he has known that delight is the root of suffering &amp; stress, that from coming-into-being there is birth, and that for what has come into being there is aging &amp; death. Therefore, with the total ending, fading away, cessation, letting go, relinquishment of craving, the Tathagata has totally awakened to the unexcelled right self-awakening, I tell you.&quot;

Also see this answer on How to interpret cessation which explains there are two types of cessation -- with feul remaining and no feul remaining. (mentioned in Iti.044)