Looking forward to that conversation ... P.S. ... love your new avatar.
It begins fairly simply. Though much lip service was done to distinguishing them, there has never been a valid and adequate distinction between aidios (eternal) and aionios (everlasting), though both Greek words are translated with both English words. (And aidios is only used twice in the entire NT text.)
So ultimately, the best we've been given is two "kinds" of eternity (most notably by the Scholastic Latin, Thomas Aquinas). But that's not nearly enough, and it affects everything else in a cascade from that foundation if it's false.
This is why there were so many early "competing" formulaics for Theology Proper. They were all compensating for having the same shared insufficient foundation, and every debate was framed incorrectly.
The Arian conflict utilized Incarnational terms by asking... "Was there a time when the Son was not, or not?" WRONG question. There was not time until it was created in all forms to govern both the heavenly realm and the cosmos.
Most began with the impression and passive presupposition that God was eternally in heaven and created the cosmos. But God is Self-conscious Self-existence, and is timeless and non-spatial (among other significant incomunicable attributes). So how did the uncreated God create the heavenly realm and "get in" there?
Heaven is not a giant eternal God jar. Heaven is created and everlasting, just as the cosmos was in its original state that lapsed at the Edenic scenario in the garden and will be restored.
The Trinity doctrine, just like all other ancient formulaics, gives no consideration or answer for "how" Father, Son, and Holy Spirit are eternal apart from heaven and the cosmos, but also have real presence in both created realms. How were they, as uncreated, compatible in any sense with creation to "occupy" it, and how did that occur?
God created aeviternity (everlasting) as endless durative time in whatever form it is in the heavenly realm. Eternity is not a "place" or a "thing", nor is it any form of time. Eternity, as one of His primary incommunicable attributes, is relative to God's existence alone.
That's why there's no "eternity past". That's a fallacy of shallow men's minds, grappling with high things to express in a lowly manner. Eternity is the timelessness of God. Everlasting is the created endless time of the heavenly realm and the cosmos apart from its lapse and restoration.
The eternal God created everlasting. But the quality of everlasting life from God is relative to its source; so in this context, everlasting life can be referred to as eternal life. But not because we become eternal as uncreated with no beginning; but because the quality of the source that gives that life is eternal, and from which comes the endlessness of everlasting.
That's just a quick summary, and doesn't yet touch on the procession of the Logos and Pneuma as the Son and Spirit; but there are many facets to the minutiae of all of that, and some of it needs to be subtly corrected from the work of the Cappadocians in the late 4th century.
When the foundation is subtly insufficient, that which is built upon it is subtly in error. That's my lifelong pursuit. To introduce the reconciliation that will establish more particular boundaries for Theology Proper that resolve the many remaining paradoxes that are left out of genuine sense of respect and awe for the mysteries of God.
But musterion is "the mystery revealed", not concealed. The Son needs to be fully known as the eternal and uncreated Logos of God, who is the Father. All the Unitarian, Arian, Sabellian, and other nonsense can be reconciled to the truth. But the Trinity doctrine needs a touch of that, too.