FYI, there is a 93u+(20120801) fork only for bugfixes at https://github.com/ksh93/ksh Maybe some patches can be cherry-picked.
A beta release of 93u+m should be available soon: https://github.com/ksh-community/ksh/issues/18#issuecomment-774994556 I propose to put the beta release to Fedora 34+ as soon as it goes out.
The beta release is out: https://github.com/ksh93/ksh/releases/tag/v1.0.0-beta.1 I propose to put it to Fedora rawhide, assuming it builds and passes the upstream tests.
dist-git commit: https://src.fedoraproject.org/rpms/ksh/c/3222ac2b59c042bb60413bdc53e2301b7ecc1555?branch=rawhide