OK, trying to get some clarity in all this. So I have devised an example. I'm keeping the amounts small to avoid complications with any non-concessional contributions cap.
Mr Retired is 69 years of age and has a superannuation account balance of $300K. They have never made any after tax contribution (neither concessional nor non concessional).
Of that $300K, $10K is listed on their benefit statement as "Tax Free" and $290K as "Taxed".
The entire $300K is withdrawn and deposited into a superannuation account as a "personal after-tax contribution".
So, now then listed on the benefit statement there $300K as Tax Free and $0 as Taxed.
This is converted into a superannuation pension with 6% withdrawal.
In the first year the pension fund earns 10%, and now has a rough balance of $312K ($300K + $30K - $18K).
Does this result in a situation where there is roughly $282K listed as Tax Free and $30K as Taxed?
Of course, this is simplistic ....