Trinity is not a nuance.
When we unfold the trinitarian life of God in His gospel work, we're not simply adding a level of detail to functionally unitarian 'God'-speak. Trinity is not just a nuancing of more basic truths. To speak of trinity is to uncover a logic which alters the way we conceive of everything, from the ground up.
Now of course we can still make simple looking statements like 'God must be worshipped.' But what it means is I'll subject all of them to thorough critique. Specifically, I will refuse to conceive of those sentences in unitarian terms. Instead I will ensure that the Subject of that sentence can refer to each Person of the trinity and to the triune life as a whole. And I will think hard about how these explicitly trinitarian considerations affect the truth of the proposition. In other words I will resolve to conceive of both the Subject and the verb in these sentences in explicitly trinitarian terms.
But does this really make a fundamental difference to 'simple God-talk'?
The command 'God must be worshipped' can be applied to each Person and it can be applied to the triune life as a whole. So it passes this minimal test. But as we consider these triune relations, we realize that the Persons glorify each Other. They are not simply recipients of worship (which the simple 'God' is) - but they are themselves worshippers. More than this, we worship God only when we are rightly included in their worshipping life. We must be in Spirit and Truth to worship the Father. And we must first be the objects of His love and glorification before we find ourselves participating in the love and glorification of God. Do you see how the Subject and the verb are radically affected by trinitarian analysis?
Or think about the concept of 'God's monarchy' - i.e. that God exercises a singular rule. As a simple (functionally unitarian) concept this would lead us to think of God's rule in ways fundamentally opposed to a trinitarian understanding. Trinity doesn't mean there are three thrones and it doesn't mean that the Lamb is off-centre on the throne. It means that the Father rules through (and only though) His Spirit-anointed Son (cf Psalm 2). Yet without this trinitarian dynamic being explicit, the triune God's monarchy will be misunderstood.
Or again, think about this contentious statement: 'God is unoriginate.' It was a favourite of Arius - what do we make of it? It seems completely logical. It seems to be guarding against things we want to guard against. Surely full divinity cannot be predicated of anything that has an origin outside itself. Right? We can't have divinity that depends on anything outside itself can we?? Well, on this understanding we look at the Son Who has His eternal origin in the Father, and we conclude that the Son is less than fully God. That's the very logic Arius used and it's just why Athanasius got so picky and said that Arius should not name God from creation and call Him unoriginate but name Him from His Son and call Him Father. In other words - unless from the outset you define God's nature with the Father-Son reciprocity in mind you won't be able later to call Jesus God - not fully God.
'God is unoriginate' is an example of a statement that sounds good and seems to protect important things. And it might be able to be applied to the Three together (the Three do not have their source of life outside themselves) but it is unwise to make the statement simpliciter. And it can lead to heresy when it is applied to particular Persons.
The problem is that it has begun in functionally unitarian 'God-talk' and it simply cannot be rescued by trinitarian nuance. That's not the direction of travel. We can't go from functional unitarianism to trinitarian discussion as though we're moving from the synopsis to the novel. The comparison is more like two competing treatises.
When we talk trinity we talk about basic things - fundamental, bedrock things. We don't simply uncover extra depths when we lay bare the perichoretic life of God. Actually we discover an essential logic that requires articulation according to this trinitarian dynamic.
Trinity is not a nuance.