Both the current v1.13 and beta v1.14 firmware use a fixed UDP packet size of 16 azimuth blocks. I recommend looking at the v1.14 user guide, which does a pretty good job outlining the structure of an azimuth block. Also see the reference link below.
To answer your other questions, no, it's not one packet per revolution. The number of packets per revolution will depend on the LiDAR mode, e.g., 512x10, 1024x10, 2048x10, etc. These numbers represent <azimuth blocks per revolution> x <revolutions per second>. I suppose you can adjust these to meet your data rate requirements.
I hope this helps!