Report intervals faster than every 2 seconds tend to cause performance issues in MPS.
GPS devices tend to be only accurate to about 10 meters, so a setting of 6 meters could have an impact. Even with a higher setting, the unit position should settle to the final position, i.e. it will "catch up" when the report interval passes and won't be left 100 meters away...
What version of MPS are you running? There was at least one performance fix in the last couple years to the Patrol Dashboard that was not proximity related (if I recall correctly).
As for how you should adjust the settings, it depends on a number of factors like what hardware is in the clients and how many units are being sent to MPS.
Have you restricted the number of sentences coming in from the GPS? If its NMEA, you really only need the RMC sentence. It's best to restrict it at the GPS device itself, but if that's not feasible then set the acceptedSentenceTypes setting.
But you should keep in mind that MPS is not a real time system, it's a situation awareness tool but not intended for instantaneous, high resolution live tracking of units. It's coded in javascript and HTML inside of web browser objects -- they are slow by nature. (I've done hard real-time systems, e.g. a helicopter flight simulator that required 25 ms update rates or the simulation failed to be mathematically accurate and shut itself down. MPS is not like that. :-) )
