There are several discussions here and will link to them.
High level, starting with 8G transmitters, it gets a bit more challenging.
To extend sensors, the auto extend does not work. The transmitter needs to be physically removed from sensor, without removing sensor. Then wait 20 minutes and then snap transmitter back on. Then treat it like a new sensor.
I have done reset (days) on 8G transmitter (via xDrip), but we have learned later 8Gs may have later software versions that prevent it. 8Hs may have even more limitations. The auto restart does not work, since transmitter now expects a disconnect of sensor, to make it think the sensor was physically changed.
I don’t have tslim, but use dexcom G6 Receiver for the sensor start/stop, and xDrip follows same data when Native is set. The Tslim pump should work same.
With 8G transmitter, I found it gets confused if I try start or stop sensor from xDrip.