The reason the info is proprietary is that ANT channels are designed to drift and coexist with many other channels in RF environments, and it is impossible to give detailed low level channel specifications without revealing details of the proprietary algorithms. In other words, the "jitter" will change depending on the circumstances, but exactly how is propriety.
I think I can answer your question though. If you are looking for a guarantee of 1 uS tolerance, ANT will NOT be able to meet this. The ANT clock source is a 32.768 KHz crystal oscillator with a frequency accuracy of +- 50 ppm, as defined in the datasheets. Therefore it cannot do anything better then around 30.5 uS of tolerance, with 50 ppm of drift.
I hope this answers your question!