@everydayupsanddowns You use a 640g pump so I assume you are talking about sensor/pump integration, and using finger tests to check your integrated sensors. That is a seperate issue.
Libre sensors are as accurate as finger tests the majority of the time. When using Libre I run the data through my phone (blucon or miaomiao will work) then calibrate twice a week with finger sticks while glucose level is at 5mmol.
If your libre sensors are constantly giving bad data I would suggest going back to finger sticks full time.