My paid plan was for 29 Jun 2020 - 29 Jun 2021 looking at this page> https://nicepage.com/User/Orders/Subscriptions What's the most up to date version I can install without triggering the lower tier...

I would like to know what difference there is regarding the Full design customization option between the PERSONAL & BUSSINESS versions.

You said the there is now a list of 'available versions' in the dropdown menu in the program. I do not see this option in my dropdown menu. : ( see attached image