You do not need to pay any attention to your damper if you are changing the travel to be shorter than what it is now, because the damper will just compress to accomodate for the decreased travel. Yes, you can even decrease your 180mm fork all the way down to 130mm and your damper will simply compress to the new travel without any negative effects.
However, if you are extending the travel of your fork, then you need to check to ensure that you are not going above the maximum travel of your specific damper. Below is a list of each damper that fits in the 2017-2020 Fox 36 chassis along with their maximum travel according to the fork's wheel size:
Maximum Damper Travel (DO NOT EXCEED):
- RC2 Damper Maximum Travel = 29" Fork = 160mm / 27.5" Fork = 180mm
- Old FIT4 Damper Maximum Travel = 29" Fork = 160mm / 27.5" Fork = 180mm
- GRIP2 Damper Maximum Travel = 29" Fork = 170mm / 27.5" = 180mm
- GRIP Damper Maximum Travel = 29" Fork = 170mm / 27.5" = 180mm
- New 2020 FIT4 Damper Maximum Travel = 29" Fork = 160mm or 170mm depending on CSU model (must confirm with Fox) / 27.5" and 26" are both 180mm maximum with all CSU's