This is valid for the Ryzen 3000 "Matisse" processors and Ryzen 4000G "Renoir" APUs. CapFrameX shows an improvement from core-to-core latency of 56.9ns with AGESA Combo V2 1002 to 48.9ns with AGESA Combo V2 1081. ComputerBase also reports performance gains of 3 to 7 percent in this area.
Furthermore, it seems chips like the Ryzen 3950X are able to hit their max Boost frequency more often with the latest AGESA microcode.
Sorry, correct are the following AGESA versions.— CapFrameX (@CapFrameX) September 10, 2020
Latency core-core: 48.9ns = now (AGESA Combo V2 1081)
Latency core-core: 56.9ns = previous (AGESA Combo V2 1002)