I am not seeing anything about CRR in this discussion? I see a few comments about how a heavy rider would be no different speed in the draft. That would not be true if CRR is taken into account.
The CRR on zwift tarmac is very low, so the extra resistance from being heavy is negligible.
You do notice it on non-tarmac surfaces, less so since they reduced the CRR on those too.
Did a race earlier 160-270 where two riders did PBs, both hit 3.4 W/KG for 5 minutes,
Finished 6th-100KG Rider 302 points 348 watts
Finished 2nd - 84 KG Rider 252 points 287 watts
Big difference and advantage on hilly courses especially if it scales like that then a 60kg rider hitting the same 3.4 W/KG will have a score of roughly 180 points.