Smoothing blood glucose data
AAPS works best when the blood glucose data it receives is smooth and consistent. Some features like 'Enable SMB always' and 'Enable SMB after carbs' can only be used with a nice-filtering BG source.
Dexcom G5 App (patched)
When using Dexcom G5 App (patched) your BG data is smooth and consistent. There are no restrictions in using SMB.
xDrip+ with Dexcom G5
Smooth enough data is only delivered if you use xDrip G5 'OB1 collector in native mode'.
xDrip+ with Freestyle Libre
When using xDrip+ as your data source for Freestyle Libre values until now you cannot activate 'Enable SMB always' and 'Enable SMB after carbs' within SMB because the BG values are not smooth enough. Except this, there are a couple of things you can do to help reduce noise in the data.
Smooth Sensor Noise. In xDrip+ Settings > xDrip+ Display Settings ensure that Smooth Sensor Noise is turned on. This attempts to apply smoothing to noisy data.
Smooth Sensor Noise (Ultrasensitive). If you are still seeing noisy data in xDrip+ you can apply more aggressive smoothing using the Smooth Sensor Noise (Ultrasensitive) setting. This will attempt to apply smoothing even on very low levels of detected noise. To do this, first enable engineering mode in xDrip+. Then navigate to Settings > xDrip+ Display Settings and turn on Smooth Sensor Noise (Ultrasensitive).