I couldn't agree more. But aren't you promoting the same thing by judging one of God's Commandments given in Exodus 20, as "not a moral command", and then pitting that LAW against the other Laws defined for us in Exodus 20?
As an isolated argument "the 4th is not innate moral action but the others are" I am no different, I'm isolating the 4th as a "have not" law over a "have". But that's not my motivation, rather it is to challenge this terminology "moral law" when used to isolate the 10. What makes the 10 more moral than the others? Christ himself quotes outside of the 10 when quoting the greatest, is that not enough? In a strict sense, moral is a poor word to use to separate which laws are better than others because you're right, we should not be making qualitative judgments on these laws and the whole law should be received the same.
Sabbath law is complicated and it can have moral alignment as it pertains to monotheistic practice but in an ancient landscape that is driven by pagan symbolism. It is rooted in the 7th day yet where is the 7th day rooted? Sure in creation, but where does 7 come from? A critical study would reveal that the number 7 already had strong value in Semitic or ANE cultures derived from lunar activity, going back further than Abraham and from that, pagan rituals were developed and rooted in daily practice. The 7 day week may be something unique to Hebrews but the reason behind why 7 as a value is not unique to Hebrews and has deeper roots. There was already pagan practices and pagan ideologies in keeping the number 7, including counting days, notably the Babylonians saw the days 7, 14, 21, 28 as evil days and nobility would hide away during these days (a "rest adjacent" concept). It's not that the Hebrews borrowed or adopted 7 or other cultural practices like Babylonian, which are distinct; it's that they inherited it, they were born into this system, and it was already established values, but instead of rejecting it, they used it to point to God.
Commandments 1-3 are a bit redundant, critically speaking as all can be implicit in monotheism so don't need to be said yet, because of wide practice and outside influence, monotheism had to be a belaboured point. It was not just "no other gods" but clarification for graven images too (despite it basically being the same thing) and not taking God's name in vain. On top of all that it was also how to keep 7, which was needed to be defined as there was already a wide practice that was not consistent with the first 3 commandments. So 7 is intentionally redirected to be rooted in monotheism over lunar activity (which is probably also why the Hebrews don't align 7 day weeks with lunar months using extra days like the Babylonians) while at the same time pointing to a monotheistic creation origin.
The 4th is moral in the sense it rescues 7 and uniquely defines it to redirect pagan influence of the number/day to worship and rest. Routine rest can also be seen as a moral responsibility for healthy living as individuals and communities, this is coupled with the rescued number of 7 to make an ordained day of rest used for worship of God. It's remember the Sabbath day to keep monotheism over remember the 7 day because innately 7 is special (that all their pagan neighbours would say). It is recognizing something that would have strong pagan influence, leaning into it and redirecting it to worship to God as well as breathing into it theological and redemptive significance. Like creation, the 7 day practice and the number 7 itself also has it's origins in darkness where light is spoken into it and new life, along with meaning and purpose breathed into it. Creation is a part of this redirection, so is the sabbath law.
Today the day can be decoupled from these requirements as there is no longer a purpose to rescue it from pagan influence. Certainly, there is a different kind of cultural creep happening where you can say 7th day value systems are still needed and still used as a polemic but there is no need to directly rescue the physical day from corruption; but rather the need and polemic focus should be in ourselves over a day. In this respect, the 4th is deeply embedded in a monotheistic-centred morality purposed at sanctifying our corrupted ways and redirected to an upward focus. It served as a polemic to surrounding nations while Israel served as the priest, showing this upward focus and this still can be the focus today. the day and number don't carry the meaning they did in ANE culture and have become culturally irrelevant in carrying the purposed message, instead Christ is the focus that continues to carry this meaning.
This is the long way to say the sabbath law is moral but it shows how deeply impactful these laws are to the place and time they were presented. (because isolated ritual rest has no moral significance today). It's not about if it's moral or not, they were all morally centred (even the boring ones) and all about redirection to an upward focus with an outflowing of justice, mercy and compassion, even to spread that outwards to all the world. But the letter itself today may not easily align with those goals using cultural moores of today so it is not the letter we continue to spread but Christ who fully captures it (and of course he is the overall purpose) and it is he we preach, not the letter, and he we spread, not the letter. Christ's law is loving God first (that upward focus), then loving neighbour as yourself (that outflow focus). It's a heuristic approach to keeping law, and polemically speaking, it contrasts both legalism of the law and those outside of God.
So it's all moral, but if all we see is the surface letter and labels, then we've turned it into something else that Christ speaks against, even using labels to pit law against itself, which is self-destructive and logically incoherent. I get the protest to the language saying Christ does away with law, but the thing we do need to embrace is the action that Christ does to law (whatever word we use to describe this), he does to all of law, and it's not selective, there is no special law that is above or in parallel with Christ, it's all inferior to Christ. Whatever Christ did to circumcision and the sacrifice, he also did to the 10 commandments. So this requires us to improve our language and not be caught saying law is thrown away or erased or abolished (or whatever throw-away word we use), but that it is valued and kept wholly through Christ.