I think when Bhante is giving his alternative view of the 7 purifications he might be limiting his use of the terms "purity and "purification", I see that there is a difference between say, "purity of view" and "purification of view". The former being an attainment, the latter being a progressive, active practice that builds towards the former attainment. I see some parallels in the development of along the seven purifications to the cultivation of Paramis, where the lower ones, support the higher ones and vice versa till purity is achieved in the 'normal' scheme of the Suttas. Much Metta🙏