Latency times

I got the SP up and running. I had a problem at the beginning when I used default setting for the serial bridge. The latency times were too large and also the data was chopped into small packets.
After setting custom configuration the latency time was reduced to 100 ms (what is the specification?).

The question I have is following:

What are the latency times for the SP module and for the Digi connect ME and is there some way of optimizing them (reducing number of services not in use)?