I feel like the charts do need a bit of an update. At least a blurb somewhere on body condition or even including a body chart.
As far as for particular snakes...
The weight can be very subjective. Photos would be the best judge.
For example... I have a male that weighs 2200g. He's not overweight but most might balk at that number. He eats small rats every 2-3 weeks.
I'm 5'10... he's a big boy.
Another thing to consider is because of how these animals are built for fasting as mentioned above, are the signs you seeing actually fat? Some of my males will hold onto waste until the back end looks like a big ol sausage. If I wasn't aware of that snake's habits, it could be confused for something else.
Also, weight will flux depending on the season as well so definitely keep a close eye on any animal that you try to manage the weight on.