* The Frankfurt School on the "culture indutsry", which is the effect of capitalist mode of production on our culture (specifically art and within that, most focus is on the literary arts though it easily applies to music too).
* Guy Debord's Society of the Spectacle, describing the world at a deeper level to as Marx put it, or rather, a deeper analysis of our society from a situationist point of view.
* Marx's concepts of commodity fetishism and alienation, describing the effects which the capitalist mode of production has on the psychological well being of the working class.
* The extensions from this, again I must refer to the Frankfurt School, I'm in the middle of a book called Escape from Freedom by Erich Fromm. He wrote a foreword to the second edition 25 years after its first publication, in which he claims that the conditions he describes of the freedom of man in capitalist society have become even more important to analyse for our wellbeing overall. It is a psycho-sociological work, and I haven't read it in full, I'm slowly making my way through it, however from what I've read I would recommend it for its interesting point of view.
* For a critique of the notions of tolerance in society and pluralistic democracy (which is supportive of "true" democracy, of power of the people as individuals rather than religious, ethnic or social interest groups), I recommend in particular the first and third essays (the third by Marcuse, the first by Richard Wolff) from A Critique of Pure Tolerance
 I must first note that "commodity fetishism" is absolutely not about how people are materialistic and value material wealth over spiritual or moral action. It is about how through the market, the interactions between people themselves are hidden and proxied such that the commodity itself is fetishised, to use that term in the sense of meaning "of unnatural excessive focus" https://www.marxists.org/glossary/terms/f/e.htm#fetishism
 Alienation is a concept that Marx borrowed from 18th century philosopher G.W.F Hegel, it's one which is generally deeper than how Marx uses it, and there are others who interpret it differently to Marx. Here is the Marxian view, though there are others you can find. https://www.marxists.org/glossary/terms/a/l.htm#alienation
 https://en.wikipedia.org/wiki/Escape_from_Freedom and there are links to download mobile-friendly versions of the work here: https://libcom.org/library/escape-freedom
 PDF version here: https://monoskop.org/images/5/55/Wolff_Moore_Marcuse_A_Criti...
"If the means of production can themselves be copied for a cost of zero, this theory would not necessarily apply."
"If a good can have a marginal cost of zero, it is special and the consequence of taking over the means of its production may diverge from what the theory suggests."
Let me give an example of what I mean by "clear" with a passage from Thomas Jefferson:
"If nature has made any one thing less susceptible than all others of exclusive property, it is the action of the thinking power called an idea, which an individual may exclusively possess as long as he keeps it to himself; but the moment it is divulged, it forces itself into the possession of every one, and the receiver cannot dispossess himself of it. Its peculiar character, too, is that no one possesses the less, because every other possesses the whole of it. He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me."
He's not talking about means of production but incentives for production. But the insight is clearly stated and apt for digital tech.
So are there any examples like this from those references that are still apt when applied to zero marginal cost digital artifacts (files), factories (compilers), or publishing (bittorrent)?
I'm not so sure if zero-cost reproduction of means of production would render Communism unnecessary in the eyes of the theorists I have mentioned. People would still effectively need to sustain themselves via wage labour, though they pay wages to themselves. This is forgetting the fact that most of the products made to my knowledge can't be made using zero-cost means of production; bread for example requires not only the bread machine, but also the mill, the labour input to sow the seeds of the wheat, to reap it, to grow the yeast, etc.
I would not say that the concept of Communism applies to goods which require zero cost to reproduce - I think this is for two reasons; firstly, one could say it is already Communistic that the means of production for digital objects can be considered to be producing commodities with very low value, tending to zero though not quite zero (electricity and maintenance of computer comes to mind), though as I will later note, considered in isolation then they only have use values and thus a PDF isn't a commodity, so software doesn't count as MOP; secondly, wage labour, which the Communists aim to liberate the proletariat from, is not necessary with the factories and publishing you mentioned - as such, most such instances, such as my laptop I'm using now or your phone you publish torrents with, these objects are personal property, not private.
But there is of course still the problem of who creates (labour) the computers which are used for near-zero cost reproduction, and indeed their maintenance (labour) and powering (labour). These three instances of labour is what Communism concerns itself with, rather than reproduction.
So while I don't know of anyone who has written about it (certainly not Marx, though I wonder about modern day Communists), I think I'd agree with what you said originally - the theory of Communism does not apply when we are talking about files/compliers/torrents, primarily because when considered in isolation, these do not require wage labour. It's similar to how Communism doesn't apply, for example, to the case of the garden which you personally tend to in your back yard.
Edit: Communism, being an anarchist ideology, is inherently opposed to the ideas of "intellectual property", copyrights and patents in the first place. I feel as though most Communists would very much agree with Jefferson, as I do. What's rather strange is that Communism, to some, is considered the legitimate offshoot of classical liberal thinking, especially considering the warnings or outright condemnations of the usage of private property by early liberals.
I do not consider neoliberalism to be a modern Marxist invention, though I can't claim to know about its history, and of course hitsory is extremely important to reveal a movement's origin and aims. My reasoning is from the idea that neoliberalism supports private property and what Marxists see as a class society. It does not aim for the abolition of these classes, but rather its stated goal is to acheive development within the capitalist system.
In this way, neoliberalism is identical to social democracy in its overall aim - it works within a class society to try and bring better conditions, though people frequently criticise neoliberalism as being uncaring of the poor, the Marxist would say a similar thing about social democracy.
For a read by a thinker inspired by Marx, I've heard good things about David Harvey's A Brief History of Neoliberalism. I have not read it, so I don't know if I should recommend it, but since you mentioned modern Marxists, and he is one, it may be of some use to you.
I'm not saying much is wrong, just that it's neither new or insightful
And you're probably being downvoted because your criticism is neither specific nor substantiated, and fairly snide besides.
But I liked the article overall and think it's a good starting point for discussion.