Have you taken a look at DBOS? [0]. It's like Temporal but no depenency on an extra coordination service. A lot of the concepts are similar.
Thanks! I hadn't seen it until now. Looking at it, it seems similar in the sense that it focuses on saga-like functionality (workflows in their terminology), but different in the sense that, like Temporal, it's only concerned with workflows defined entirely within the scope of a single service (I should probably say "a single codebase"). However, it definitely seems like a good candidate to ping if it would make sense for them to use structured cooperation in some fashion.