I think this question is touching on two related yet separate debates.
- Should, in the Hebrew Bible, the very common occurence of "malach YHWH" and similar constructions be translated as "The Angel of the LORD" and be a reference to YHWH himself, or simply as "a messenger/prophet of the LORD".
This relates to the question of definiteness as well as identity (e.g. is this a title?). This is effectively a debate between Christians and Jews of the old testament and touches on some very interesting ambiguities in Hebrew -- e.g. in a construct form the article is applied only to the absolute noun at the end, but YHWH cannot take an article (or any modifier) and so definiteness has to be determined through more oblique means. The full argument then looks for citations throughout the Hebrew Bible as well as theological beliefs -- e.g. requesting to remove your sandals for you stand on holy ground when in front of malach YHWH (ex 3.2-6), and not dissuading people who bow down to/revere malach YHWH, and various passages where malach YHWH declares himself to be YHWH, etc. For an extended version of this debate and all it's grammatical and theological arguments, see the noted hebraicist McCaul, pages 9-27. https://archive.org/details/rabbidavidkimchi00kimcrich/page/8/mode/2up
As part of this larger debate, we need to understand that "malach" can indeed be interpreted as any messenger, including human messengers, and so we rely on a long chain of arguments to make this case, bringing both grammar and theology to bear on resolving the meaning of this idiom used more than 500 times in the Old Testament, from Genesis 16.7 to Zechariah 12.8
But once you have "malach YHWH" is a special identity that has the same name as "YHWH", then this is the argument that the angel of YHWH - the one who appeated at the burning bush and said "I am YHWH" -- was the one that gave the law to Moses on Sinai.
- The meaning of the Greek in Acts 7.53, translated in the LEB as "directions of angels" or "ordinances of angels".
you who received the law by directions of angels
and have not observed it!”
Here, too, the Greek is ambiguous but for slightly different reasons. First, angelos has the semantic range of "human messenger", "divine messenger", "evil spirit", "angel" or "God" depending on context (see BDAG entry for angelos). One might think of the most general translation as "supernatural ordinances". Thus there is ambiguity as to whether eis diatagas angelon "by the ordinances of the angels" in Acts 7.53 should be viewed as a similar construction to eis cheiras ethnon - "into the hands of men" (Acts 21.11), where "men" serves to denote a category rather than a specific number of men, or whether it should be read as eis apostolous Christou ("as apostels of Christ") in which the disagreement in number of the genitive is important, theologically, as there are many apostles but one Christ, thus there is a unity emphasized.
The bottom line is that these ambiguities in "ordinances of angels" is not going to be resolved by looking at the grammar of a single greek passage and so doesn't really have much bearing on the proper interpretation of the hebrew "malach YHWH".