"Well-supported scientific consensus" and "scientifically well-supported theory" are doing a lot of work when the loudest enforcers of the "consensus" consistently operate in dishonesty for strategic reasons, see e.g. the 2019 Cofnas paper: https://www.tandfonline.com/doi/pdf/10.1080/09515089.2019.16...

>hypervisor has become the OS and the traditional kernel (a Linux one in this case I presume) has become virtually * ahem * redundant.

That's the point of unikernels right there :)

Git submodules are designed for your use case, but I don't know how well they handle it.

I'm pretty sure Java's Swing uses a similar approach.

Sure, because that was the obvious standard technique in 1996. But for it to become the standard, someone first had to invent it. (And Swing in 1996 probably ran slower than Mac OS in 1986, despite Moore's Law.)