Thanks for taking the time to analyze the issue.
The P2720/24PN came first and is the look I’d prefer to maintain–better camera, better color, etc.
According to Graeme Nattress “Standards Converter with G Film Converter, NTSC to Film option” will convert the 1080i footage to 24.
If I do as planned, maintaining 24, the question is whether to edit on a 720 or 1080-size frame, and which ProRes codec to use. (I have Video Purifier which claims to be the best choice for changing frame size).
The final output will be on a large screen.
Thanks again
GW