It may appear that this is the case at first glance, but thanks to how the system works both Fast mode and Note mode benefit from being in the same privacy set since no outside observer could tell which mode a user chose. I'll quote again from a different discussion I had in the other thread:
Thanks for the explanation. I got your point and things are clear now. We just need to use the mixer in a little complicated way so it becomes harder to trace the link. Once a lot of people will start using whirlwind, it will be harder for someone to trace. Thanks a lot.
In an event when I deposit already money on the mixing address provided while the Ddos attack occur. Will the mixing process continue or the service will temporarily pause and resume once the update completed. I successfully mix already in the fast. I just notice that my deposit needs to have 2 confirmation before mixing will commence based on the set time and a problem like this might occur on this period. Clearnet version is always available whenever I’m visiting the mixer.
If you are using Fast mode and have assigned/set everything accordingly, you have nothing to worry about. Your BTC will arrive at your desired address at your pre-set desired time/delay time. This means the mixing process will continue for sure.