The traditional, orthodox concept of Heaven derives from ancient Greek philosophy - I shall call it Platonic - this can be summarised:
God - Creation - Beings
The first thing is God, alone - who does Creation - and late in Creation God makes Beings, including Man.
For Christians; God is a God of Love, whose creation is a kind of gratuitous overflow of love: so we get
God-Love - Creation - Beings
By contrast, what I will call the Pluralist concept of Heaven - which is the one I believe to be true - can be summarised:
Beings - Love - Creation
The primordial situation is of many Beings, of whom two are are Heavenly Parents - Father and Mother.
Thus God is Dyadic, irreducibly Two and not a unity (or, the unity is of two always-distinct aspects, permanently-made a unity by Love); and it is from the Love between our Heavenly Parents that Creation comes into existence (Love, being the coherence and purpose of Creation; Love harmonising the diverse elements of Creation). So we get:
Beings-God - Love - Creation
The Platonic Heaven seems to be associated with a wish for absolute, abstract, infinite perfection - and God is defined in such terms - including that God is undivided unity, of infinite power and presence (omnipotent, omniscient, omnipresent).
And this primal God creates everything else (everything other than God) from nothing (ex nihilo) instantaneously, in zero-Time (first Nothing, then Something... there can be no graduation or graduality) - including Beings, including Men.
In a Platonic Heaven, therefore, Creation remains entirely God's business, and nothing/ nobody else can contribute to primary Creation (only to secondary details within Creation). Also Heaven is perfect, so there is nothing for Men to contribute to it. Also primary Creation happens in zero-Time.
The Platonic Heaven is essentially contemplative: Man has nothing necessary or useful to Do. Man enjoys heaven, but does not add to it (because it is perfect). In Platonic Heaven; we may express gratitude, worship, may do many things - but none of them are necessary, none make any qualitative difference to Heaven.
In sum, the Platonic Heaven, is a state not a 'process'. It is a state of being, a state of communion with God, of bliss... but essentially it is static - there is no dynamic to Platonic Heaven - because movement comes from difference, from desire, from deficit... and this cannot be because the Platonic Heaven is perfection.
In distinction, the Pluralistic Heaven in a world of Love, but not of perfection. Love is understood as itself dynamic ('in' Time: Time is a part of primary reality), between Beings; and therefore Heaven is a continuation of Creation - and for Christians it is a Heaven of active, personal participation in Creation.
This happens because Christians will be resurrected into Heaven, and resurrection is understood as becoming divine - immortal, indestructible, grown-up children of God. The actuality of God's primary Creation is opened-to the contributions of resurrected Men.
Part of pluralism is the uniqueness of each being, including of each man. Each resurrected Man brings to Heaven something unique, that did not previously exist in heaven. Every single individual Man who enters heaven therefore brings something irreplaceable to the ongoing Creation.
In sum everybody who is capable of Love and who chooses to follow Jesus, may be resurrected into heaven; and each such person has something unique and irreplaceable to contribute to God's ongoing work of Creation.
The Pluralistic Heaven is not only-contemplative (although contemplation is surely possible, and part of things) - but is active dynamic and open-endedly creative: a growing Heaven. And this Creation of Men is included in the primary and divine Creation.
Man's unique and individual contribution is woven-into Creation permanently, forever. And this is made possible by Love.
It is Love that harmonises God's creation with the contributions of many individual and unique Men - resurrected Men joining in increasing numbers with time.
The Pluralistic Heaven is not perfect, it is not closed, it is not complete, it is not outside Time... on the contrary Time (sequential, continuous, linear) is an assumed part of reality. The Pluralistic Heaven is, therefore, developing, open-ended, growing... Heaven is in-movement, is changing, has a past and a future; and changing, expanding personnel - each with an unique contribution to make to the whole.
So, we can see that the Platonic Heaven and the Pluralistic Heaven are very different places. While one may be contained within the other - only one or the other (or neither) could ultimately be true - since they each have extremely different ultimate metaphysical assumptions.