Mailman 2 --> Mailman 3 ... largely (but not entirely) done; holler if one notes any issues.
Summary on status/progres can be found here: https://www.wiki.balug.org/wiki/doku.php?id=system:mailman3#mailman_2_--_3_m...
There were some glitches, notably with import21 ... and did find a work-around(/fix?) for that, and also had some issues with archive import+indexing, but seem to have made it past all that now (though still have some more validation checks to do, etc.).
And note that thus far, the merging of archive from the (temporary) balug-test3@lists.balug.org to balug-test@lists.balug.org is still pending. In the meantime, those archives are available here: https://lists.balug.org/mailman3/hyperkitty/list/balug-test3@lists.balug.org... And the balug-test3@lists.balug.org is also mostly locked down to prevent changes (no new postings or subscription/membership changes).