I believe the general rule Kelly gave out at one point was limit the pre-wod mobility work to things you need to do in order to get through the wod. Then afterwards work on whatever was heavily taxed or is sore or is tight and needs to be worked on. I personally do not believe that an hour of mobility is not too long. I have heard of dancers who spend at minimum of 2 hours stretching each day so one hour is not too much. If you want to break it up i think that is ok but it is really up to your preference. From personal experience i would say do not just rest after a workout or you will feel very sore, just do a little to flush out whatever is going to be sore. I am not an expert, this is simply advice from what I have learned watching Kelly’s videos and through my own experience as a mobility enthusiast.