I graphed Weight vs Finishing position for a couple of the KISS Community League races just to see if there was any correlation.
For the Volcano Flat Reverse Race (https://www.zwiftpower.com/events.php?zid=162691)

For the Innsbruck Ring Race (https://www.zwiftpower.com/events.php?zid=159334)

For the Watopia Mountain Race (https://www.zwiftpower.com/events.php?zid=166630)

So ... a slight correlation favoring heavier riders on Volcano Flat Reverse, is less on the punchy Innsbruck Ring and it disappears entirely on the Watopia Mountain stage.
For the Volcano Flat Reverse Race (https://www.zwiftpower.com/events.php?zid=162691)

For the Innsbruck Ring Race (https://www.zwiftpower.com/events.php?zid=159334)

For the Watopia Mountain Race (https://www.zwiftpower.com/events.php?zid=166630)

So ... a slight correlation favoring heavier riders on Volcano Flat Reverse, is less on the punchy Innsbruck Ring and it disappears entirely on the Watopia Mountain stage.