See https://github.com/w3c/web-platform-tests/pull/9672 for tests and https://github.com/whatwg/html/pull/3508 for the fix for the standard. Seems Safari is alone in not throwing for this case. (Given it's three browsers against one I haven't tried to figure out what Safari does instead.)
Note that per https://github.com/w3c/web-platform-tests/pull/9672 and https://bugs.chromium.org/p/chromium/issues/detail?id=816447#c3 in particular more changes are being considered here. I hope to be able to update the tests later on to match these changes. Feedback appreciated.
Those changes are now made, so now Safari fails a couple more tests. A couple failures are related to ImageBitmap and OffscreenCanvas not being transferable and some are about duplicates not throwing or the wrong exception being thrown.
We are still failing some WPT tests: https://wpt.fyi/results/html/infrastructure/safe-passing-of-structured-data/transfer-errors.window.html?label=experimental&label=master&aligned=
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