John Cowan, co-author, with Wolfgang Corcoran-Mathe, of SRFI 189: Maybe and Either: optional container types, has asked me to announce "last call" for this SRFI. He believes that it is ready for finalization, but would like to give reviewers one last chance to submit corrections and feedback before we finalize it.
In particular, I appeal to anyone reading this to try the sample implementation, run the tests, and send feedback about your results.
If you're interested in this SRFI, please give your feedback via the SRFI 189 mailing list before 2020-06-10. After that, assuming that no major revisions are required, we will declare it final.