Queer Marxism would be radical & dialectical materialist feminisms updated to the 21st century. So maybe look at transfeminist writers but I don't have any recs yet unfortunately. I'd say a queer Marxism would be an update on the old scientific socialist analysis on the origin, evolution, and abolition of the family as well as an updated class analysis of the patriarchy that keeps trans people and lesbians in mind. I've seen some informal writing on this but don't know anything long form yet. The Gender Accelerationist Manifesto does some of this. It's a dialectical materialist analysis but written by anarchists interestingly enough.

I don't know if this is exactly what you are looking for, but John D'Emilio's Capitalism and Gay Identity is a very famous paper that argues for a historical materialist understanding of gay identity. The paper is actually fairly old (it was written in like 1983 or something), so it actually predates much of queer theory, but its absolutely still worth reading if you haven't yet

I agree it is a sorely under theorized issue, and it is striking just how many groups during the New Communist Movement came to some pretty backwards positions for instance. This document, published in 1975, deals with these incorrect lines: https://foreignlanguages.press/wp-content/uploads/2021/11/S21-Towards-a-Scientific-Analysis-of-the-Gay-Question-3rd-Printing.pdf

Definitely not related to queer theory as an academic discipline, but should be relevant nonetheless.

I can't recommend any texts off the top of my head. My impression is that a new queer Marxism is something that is still early in development, so to speak. I don't think we can say just yet who the most important theorists of this topic might be. It's something I am also very interested in, so I will be watching this thread closely. I think an important difference between a new queer Marxism when compared to the Marxism of the previous century, would be the inclusion of the lumpenproletariat into a revolutionary model. It's my impression that a lot of important Marxist theorists of the previous century were prone to being very dismissive of the potential role of the lumpenproletariat in a revolutionary framework. A lot of the time, they were referring to woman sex workers when they hit this regressive note. These days we see this role being filled in great proportion by queer especially trans people. So it has been my view for some time that a revision to the view of and role of the lumpenproletariat, as compared to now-orthodox 20th century Marxist doctrine, must be essential for achieving a true new queer-Marxism synthesis.

Sorry if this is poorly worded or kinda vague, I'm a bit drunk and did my best to elucidate my thoughts.