MAC layer key enhancements in 5G SA

Hello Everyone
I have a question and would be helpful if someone can help me with the answer.
From the UE perspective what are the key enhancement at the MAC layer in 5G SA as compared to that of LTE?
I could analyse some of like BSR (CE) and HARQ procedure.

2 Step RACH in R-16 in NR.

Anything on PHR and SR?