Hello,

> Any objections to installing a copy of Mailman and setting up an
> experimental mailing list? Is it a really bad idea for some reason?

one not so obvious thing is that in the wild, the overwhelming
majority of projects uses mailman2. mailman3 is a complete rewrite with
a different user interface. It's best to treat them as separate
projects when evaluating a solution.

Regarding alternatives that haven't been mentioned yet, Sourcehut does
provide (among other things), a mailing list service [1]_. It should
hopefully be easier to set up than mailman3.

Vasilij

[1]: https://git.sr.ht/~sircmpwn/lists.sr.ht