I only tried multi cores / socket with a windows 10 and windows server 2019 guest. If I use 2 socket with 2 cores or 1 socket with 4 cores I have the same performance in the guest os. The guest os also shows me virtual cores instead of real cores. So in this case I see no different. Years ago the feature were implemented for licensing of the guest os. Perhaps it will be used for that reason also today.