I think that every 'method' needs to be tempered with common sense.
Clearly a small rat is too small for a large female. I have on occasion given her 'left over' rats not taken. The smalls are quite funny she strikes and has nothing to constrict, only the hind legs and tail are not in her mouth. The other end of the scale is even 10% is a huge rat, 400gm, using the diameter would be a huge rat as well. She is slightly bigger around than a pop can. That is why my old adults get less they simply don't need that much.
You have to be reasonable with such things.
This post is really all that needs to be said, common sense prevails!
~~~~~~~~~~~~~~~~~~~~~~~~~~ I own:
1.0 Reduced Normal Ball Python [Peter]
0.1 Harlequin Crestie [Amelia]
~~~~~~~~~~~~~~~~~~~~~~~~~~ The other half owns:
1.0 Orange Dalmatian Crestie [Archie]
0.1 Golden Dalmatian Crestie [Banana]
~~~~~~~~~~~~~~~~~~~~~~~~~~