If I was doing sector timing I would use this style of dead strip, they are called split rail dead strips, but actually they are not dead strips at all.

Only one of the car's pickup braids is used to complete the circuit, the car's motor is not in the counting circuit, so the counter will work if you run your track in either direction. The cars will not stall if they are stopped on a split rail dead strip and you would not have to put jumpers around them.
The six lane version of Trackmate could be used with the track being split into five segments. Lanes 1 through 5 would be used for the segments and lane 6 would be the lap timer for the entire track. A start and end dead strip would have to be connected for each segment. The end dead strip for one segment would be the start dead strip for the next segment.
If you were to run a number of laps Trackmate would register the best time for each segment and the best lap time.
To convert the track for normal lap timing you would have to add some switches. You can load two copies of the Trackmate software and configure one as the segment timer and the other as the regular track.