The physicality is unreal compared to day 1. -81k men is brutal.
NIck Delpoppolo got head smashed in his video second fight. Fighitng up in weight you will eventually get hurt because the guys are stronger/heavier. You go from fighting guys who are max 160 lbs.to guys who max 178 lbs.. -81k is the most competitive division and the most brutal pound for pound.
https://live.ijf.org/gs_ger2020/contest_video/gs_ger2020_m_0081_0106