Personally I think its the Lemans Trim...swap with my brushed and all will be better

All kidding aside I was thinking could be caliper or issue with actual tire. Do you know if the tire was ever patched or filled and are they run flats? If its the caliper(s) sticking then lift the front and free spin the wheels and see what happens.

On m5 board guy had very similar experience and he swapped out the center link today as its the only part of the front suspension that he thought could possibly be the culprit. No updates yet if it worked. He did have some different variables than you did. and Yes I know theyre different vehicles. Ive pasted link in case you want to follow his diagnosis. Ive met him he is a mechanic by trade and trust his diagnostic process.

Vibration through front floor at high speed, out of ideas? - BMW M5 Forum and M6 Forums