A'Jet, A couple of points.... UCI rules are that the nose of the saddle must be setback 5 cm from the centerline of the crank. I am not sure what the rule is for Masters Track Nationals. So I encourage you to move the seat forward and up to get the feel of the body rotation and it is more comfortable to train. But in reality, you will not get a morphological exemption to have your saddle setback reduced. And if you have your aerobars at 80 cm, then you have used up the one exemption that you are allowed. That is why you see everyone riding on the nose of the saddle and some select saddles that have a wider nose for more support.

I do not get why you want to ride fixed for the 5K at the SG. I assume that will be on a bike with endurance bars. I suggest transferring the settings from the pursuit position to your TT bike and ride the geared TT bike in the SG. You will be faster in the TT position. And if there is a turnaround, you do not want to have to effectively do a slow rolling standing start in a big gear.