punctuation - Is there an "Oxford semicolon"?

I must admit that I don't use semicolon lists very often. (In some instances, I probably should have.) I will also admit that I'm neither-here-nor-there with the use of an Oxford comma. Sometimes I use it and sometimes I don't, depending on how clear I think my sentence is without it. (I suppose I default to not using it, as is (ironically) the British/Australian custom.)

But I couldn't seem to find a definitive answer on this site for whether there is a semicolon version of the Oxford comma. That is, in Commonwealth English, do semicolon lists go:

Blah blah blah; so and so; and yada yada yada

or:

Blah blah blah; so and so and yada yada yada

or (in the case of potential ambiguity?):

Blah blah blah; so and so, and yada yada yada

I found these two sources, one British and one presumably American.

bristol.ac.uk (British)

In complicated lists.

The semicolon can be used to sort out a complicated list containing
many items, many of which themselves contain commas.

Have a look at this example:

In the meeting today we have Professor Wilson, University of Barnsley,
Dr Watson, University of Barrow in Furness, Colonel Custard,
Metropolitan Police and Dr Mable Syrup, Genius General, University of
Otago, New Zealand.

In a situation such as this, only the mighty semicolon can unravel the
mess.

In the meeting today we have Professor Wilson, University of Barnsley;
Dr Watson, University of Barrow in Furness; Colonel Custard,
Metropolitan Police and Dr Mable Syrup, Genius General, University of
Otago, New Zealand.

^ As seen, no ; and is used.

grammar-monster.com (American)

Look at this list:

• John


• Simon


• Toby

This list would be written like this: John, Simon, and Toby.

Now look at this list:

• John, the baker


• Simon, the policeman


• Toby, the architect

This list would be written like this: John, the baker; Simon, the
policeman; and Toby, the architect.

^ As seen, ; and is used.

Furthermore, the British example lacks an Oxford comma in the non-semicolon list, and the American example contains an Oxford comma in the non-semicolon list.