Seems the bug will be prioritized?
That's a different issue.
Whenever I see a limitation on plain-text (and monospace fonts), I tend to avoid that client. K-9 is not one of them. Plain-text works OK with LKML and patches are very readable.
This issue is about sending a plain-text email.
https://forum.k9mail.app/t/k-9-mail-is-not-sending-format-fl...