Yes, Sean, exactly that, the cursor sat blinking on the next line apparently waiting for a response that I didn’t know how to give.
Following your instructions, I have now made an 8192 bit key and have looked at the doc at the link you gave.
I also found a reference buried in the gnupg.pdf document to a useful paper ‘doc/DETAILS’ in the source distribution which elaborates on some of the points you described.