How to understand the actual delay of the Wwise callback function? [closed]

Question

Hi, I've been using the Wwise tool to help me with some of my audio needs.

In the process of using Wwise callback function, I encountered some confusion, hope to get your help. Here are my thoughts and puzzles（Based on the Unity）:

1.About when the callback function is triggered.
Ak use the "AkSoundController.LateUpdate() - PostCallbacks()"  to notice the receiver about when to trigger a callback. It's mean the method used to notify the recipient is executed once per frame. Let's say at frame rate 30 fps, the interval between each frame is approximately 0.03s —— Suppose I put a Mark Mark 0.02 seconds into an audio file, will I get the wrong timing for the callback（I would only know the mark point was triggered in 0.03 seconds, in fact it was triggered in 0.02 seconds）?
2.Is there a way to connect two audio files almost without delay?
For example, A piece of "audio C" consists of "audio A" and "audio B"(It's like cutting audio C), In my approach, I will set A Marker at the end point of A, and then play B when the Marker information is received.But this obviously does not make a good connection (because the callback needs to be executed in frames and cannot be returned in time). Can anyone offer a better way? Thank you so much! Thank you for your attention