Originally Posted by
milksheikh
From what I was told (when the same thing happened to our DONE4), you are OK with the 21 segments for now, but should you wish to change your routing later (even after these flights have been flown), you will need to get back to 20 segments, meaning dropping something else not yet flown.
This has never happened to me and I have had up to 22 segments through INVOLs.