Slightly off topic, but while we are venting on our 2020 Supersixes I am experiencing another issue. Mine is the non- high mod version. I bought the 105 model and swapped over the Di2 group from my 2018 Synapse. I also swapped over my Campy Bora One tubular wheels. I love the bike. Huge difference from the Synapse. The problem is a rubbing on the front brakes when standing with left pedal at 6:00 position. It has been worked on multiple times by two different Shimano certified mechanics, to no avail. The shop I bought it from got a replacement fork from Cannondale and I hope that settles the issue but I am not hopeful. My theory is that the bike was designed around the high mod flex and the lower end model I have has more flex, leading to the rubbing.The sound only lasts a half second, but is not acceptable.
It is hard to find any other posts on this issue but I can’t imagine mine is an isolated one.

Thanks