I wouldn't. In fact "would rather/sooner he hadn't" sounds far less unusual to me than "had rather/sooner he hadn't".
That's the only way of using it that sounds reasonable to me, and that's how I would use it, too. I'm glad to see I'm not alone in thinking that it's totally inappropriate.I'd sooner die than eat sweet potatoes ever again. That's the only way I use it, anyway. [...] So it just doesn't work here at all, in my opinion.
It sounds perfectly fine to meHis wife would sooner he hadn't reacted so violently.
I didn't find the answer key terribly useful, DL, as I didn't know what the question was
Ooops, I failed to mention that there was a source sentence His wife would prefer him not to have reacted so violently, and a student had to come up with the sentence under discussion, being given the beggining of the sentece "His wife would sooner..."I didn't find the answer key terribly useful, DL, as I didn't know what the question was