I think the term 'bush" is what's unhelpful here. A bush and a bearing both connect two components and allow relative rotation between them. Comparison of a suspension bush with a journal bearing is the kind of confusion that can arise when the terms are used interchangeably. The only example I can think of where a bush really is a bearing (well, strictly one half of a bearing) is a bronze sintered bush, or possibly a polymer bush which might be used as a cheaper alternative to a roller bearing.
Anyway I don't think anyone's saying an oil fed journal bearing on the IMS shouldn't work; the marvel is that Porsche didn't do it that way in the first place!
Concerns re oil pressure may or may not be well placed. Of course surge is irrelevant at hot idle, but it's not irrelevant if the oil feed to your journal bearing is interrupted mid corner. A splash lubricated IMS bearing would survive surge temporarily interrupting oil pressure to other components, but that's avoiding the problem of low oil pressure rather than solving it!
Anyway I don't think anyone's saying an oil fed journal bearing on the IMS shouldn't work; the marvel is that Porsche didn't do it that way in the first place!
Concerns re oil pressure may or may not be well placed. Of course surge is irrelevant at hot idle, but it's not irrelevant if the oil feed to your journal bearing is interrupted mid corner. A splash lubricated IMS bearing would survive surge temporarily interrupting oil pressure to other components, but that's avoiding the problem of low oil pressure rather than solving it!
