My PhD dissertation was three alternative approaches to eliminating entire classes of speculation-related vulnerabilities, both the currently known variants and future-proofing against future variants that haven't been discovered/reported yet.
@markgalassi Even though I submitted the dissertation in December, the final version isn't published yet. I'm circulating a draft for feedback, though, and will make another editorial pass before it's published as a university technical report, so comments are welcome: https://cam.lohutok.net/publication/2021-ghosting-the-spectre/ghosting_the_spectre.pdf
@allison can you post a link to the dissertation?