This is more of a short musing to myself, than a real discussion of references. I'll do a full blog post on that later. Although if readers have any advice, please leave comments below!
I'm wondering at what point in the post-viva process is it acceptable to ask your examiners if they are willing to provide an academic reference? This is particularly pertinent for those who receive more substantial corrections and yet may also be applying for academic positions. In the case of major corrections for example, you may feel that the examiners would either refuse to provide one, or withhold them until the corrections have been approved. Yet another time delay and chance for missed opportunities!
Furthermore, since you tend to only meet your examiners once, how does one gauge the type of reference that viva examiner will provide? This is especially worrisome for students who maybe didn't have the nicest viva experience or encountered a particularly tough examiner.
My over-arching question is this:
Are academic referees duty-bound to inform the candidate that they would not give a good reference and should look elsewhere?
I have no idea to this, and the other issues, and would love some feedback!