I'm not convinced that simply adding support for this mode is the right solution. I don't like the idea that Thunderbird might be pushed to support piece by piece of an unofficial specification. GnuPG should not emit this kind of data that isn't supported by other implementations.
Bug 1884508 Comment 17 Edit History
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~~I'm not convinced that simply adding support for this mode is the right solution.~~ ~~I don't like the idea that Thunderbird might be pushed to support piece by piece of an unofficial specification.~~ ~~GnuPG should not emit this kind of data that isn't supported by other implementations.~~