Hello Akvan,
“Waharaka Thero mentions that the 7 lives that a saththakathuparama has left doesn’t really refer to bava.”
Yes. That is correct.
I am not sure what issue is that we are trying to resolve. Can you ask the question again?
What I have stated is that once one attains the Sotapanna stage, there will be no “eighth bhava”. He/she will attain the Arahant stage within 7 bhava.
But that COULD take more than seven jati or births within those seven bhava. There is no stated limit to number of jati within a given bhava.
Of course, a Sotapanna COULD attain Arahanthood within the same bhava too. Sometimes, one can go through all four stage of Nibbana and attain the Arahanthood while listening to a single desana.