Hi Laura,
When using the LimeSDR I struggled to meet the latency requirements, specifically getting the ACK back quickly enough after seeing the RN16. I increased the adc_rates and dac_rates to reduce this latency: there are various sample buffers in different layers of the stack, which contribute to latency, and by increasing the sample rate these buffers filled up more quickly, thus causing them to be emptied more often and therefore reducing the average latency. A factor of 3.35 was the largest number I found that wouldn’t cause the program to break - I can’t remember why larger values than this caused problems, but they did.