LT8304, demo board

Hi Guys,

for my Bachelorthesis I had to edit a flyback converter application and used the LT8304 for control. My example was a demo board with the following circuit:

I had different output values, but I got my board working! I just have three questions for my documentation:

1. What is the capacitor 'C9' supposed to do and how it was dimensioned?
2. How the values for the Snubber (R3 and C4) were dimensioned?
3. How do the resistors 'R4' and 'R6' affect the output voltage? This problem I tried to solve by studying the Block disgram in the LT8304-datasheet, but I can't understand how it works.

Maybe some of you could help me with those questions. I would be very grateful!

Greetings,

Mario