Hopefully tomli being less than a year old should not be a blocker, after all, TOML v1.0.0 is itself less than a year old.

Despite tomli being new code, it's pretty widely used. Reverse dependencies include pip, pytest, mypy, black, flit, coverage, setuptools-scm, cibuildwheel. All in all, it should be well proven in practice by the time it comes to make 3.11 stable.

It also helps that it's easy to anticipate the interface: dump, dumps, load, loads. Overall, hopefully risk here should be well within the budget of a provisional module.

That's all to say, if and when the Steering Council decides that there's work to be done here, let me know how I can help :-)