YHWH is given two titles:
YHWH, the king of Israel and it's redeemer (title 1)
YHWH, the Lord of Hosts (title 2)
To see this, look at the first clause:
כֹּה אָמַר יְהוָה מֶלֶךְ-יִשְׂרָאֵל וְגֹאֲלוֹ
| Thus | says | YHWH | king-Israel | and his-redeemer |
The vav + pronominal suffix "and+his redeemer" (וְגֹאֲל֖וֹ) means "and his/it's redeemer". We know the pronominal suffix must be third person masculine singular because it is a וֹ -- see page 3 of the table. If the dot above the vav was shifted down to the left of the mid-point of the vav, making it a "u" sound, and if it was preceded by a nun, then it would be "our redeemer" as in Isaiah 47.4, and if it would end in "chem", like in Isaiah 43.14, then it would be "your redeemer" -- you can examine the MT in all of these. But in 44.6 the BHS text - see the screenshot - has the dot above the vav and without a nun, and so it means "his/its redemeer". Thus it must reference one of the two masculine singular substantives that precede it, either King-of-Israel, or YHWH - but unless there is some reason why it shouldn't, the default referent will be the first masculine, singular noun that precedes it - it doesn't skip over king-of-israel to reference YHWH. Thus the "his" refers to king-of-israel.
Think of "John, Jim, and his dog". Unless you know that only John has a dog, the his will refer to Jim - and even if you know only John has a dog, it would be an odd construction to say "John, Jim, and his dog" as you'd more likely say "John, and his dog, and Jim". So ultimately this is about word order, which is important in Hebrew.
Therefore two titles are given to YHWH and then He declares two more:
I am the first and I am the last
Beside me there is no other
The commentaries also agree. Here is WBC:
6a The herald presents God by a double title. He is “King of Israel.”
In this empire and especially in its capital city this is easily
forgotten. When Israel has lost its Davidic king, one might assume
that YHWH’s royal status and authority over Israel have also gone.
Daniel’s struggles and those of his friends (Dan 1–6) illustrate this.
However, YHWH still claims his title and position. He demonstrates his
authority and power by bringing a new emperor to restore his city and
set his people free. He is revealed in this act as Israel’s “redeemer,
YHWH of Hosts,” in a new setting. He had redeemed Israel from Egypt at
the beginning of their history as a people. Now, with Israel in exile
and under imperial bondage again, it will take a new ransom price to
get her free. God promised Cyrus the treasures of Egypt as his reward
for rebuilding Jerusalem and freeing the Jews (43:3–4). 6b This verse
with its counterpart in v 8d states the essential core of Israel’s
monotheistic faith: “I am first and I am last! Apart from me, there is
no God!” Israel had to agree to worship only YHWH in order to enter
into covenant with God (Exod 20:2–4; Deut 6). So now she must affirm
that YHWH alone is God; he is unique. There is nothing and no one with
which to compare him (see C. J. Labuschagne, The Incomparability of
YHWH in the Old Testament [Leiden: Brill, 1966]). This singularity
applies to all time, first and last. Idol cults rose and fell, as that
period of Babylonian history showed, but YHWH stands above and beyond
the cyclical waves of popular acclaim. (1)
Hermeneia presents the two titles as two aspects of God's provision:
Yahweh is Israel’s king. Two things are bound up with this assertion.
When the royal title is given to the deity, it means first of all that
he is “king over the gods.” A god proves his kingship by acting as
judge over the gods. But because the gods do not exist (אֵין אֱלֹהִים,
44:6*), only the peoples stand before Yahweh. The denial of a theogony
is endorsed once more (44:6*; cf. 43:10–11*). But if Yahweh himself is
Israel’s king,262 then this can also mean that no human king for
Israel can be expected. It is Cyrus, the foreign ruler, who is sent to
Babylon (43:15*) to bring about the liberation. It is Yahweh himself
who wages the real battle (43:16–21*). It is he, as Yahweh Sabaoth (v.
6*).263 In the trial described in this scene too, Yahweh is probably
represented by a spokesman, as the introductory formula “thus says
We can look for other constructions in which there is a phrase referencing the diety that contains two sub-phrases which also reference the diety. In "the (king of Israel) and (it's redeemer)", the two noun-phrases placed next to each other can be said to be in apposition. The following syntax search for other examples of apposition corresponding to Diety noun-phrases results in only two hits, as per the Andersen-Forbes phrase marker dataset(3):
with result this passage and Job 27.2:
John D. W. Watts, Isaiah 34–66, Revised Edition., vol. 25, Word Biblical Commentary (Nashville, TN: Thomas Nelson, Inc, 2005), 688.
Klaus Baltzer, Deutero-Isaiah: A Commentary on Isaiah 40–55, ed. Peter Machinist, Hermeneia—a Critical and Historical Commentary on the Bible (Minneapolis, MN: Fortress Press, 2001), 188.
Andersen, Francis I., and A. Dean Forbes. The Hebrew Bible: Andersen-Forbes Phrase Marker Analysis. Bellingham, WA: Logos Bible Software, 2009.