Just correcting a couple miconceptions: It is actually a 3x2 phase for the CPU VRM. That's 3 phases with 2 ea. 44A Fairchild power blocks operating in parallel in each phase so 6 in total...so that would be (theoretical) 264A total current handling capability. It would not ever be able to actually achieve that but then it doesn't have to since even a 5950X won't draw anywhere close to that in stock setup.
https://docs.google.com/spreadsheet...CjaXyzd1o/edit#gid=2112472504&fvid=1925177101
Any performance compromise will be entirely relative for a couple reasons. First, there is always a performance compromise when putting a powerful CPU on a tiny motherboard and in a small case like a mini-ITX would use. Second is what your expectations are with respect to how you're going to use it.
In a full-stock setup with excellent case airflow with an average mix of productivity/gaming workloads I don't think you'd notice any difference beyond the normal variations everyone sees in performance. But cramp it in a highly compact m-ITX case that doesn't provide airflow over the VRM, set a high/fixed all-core overclock and leave it doing (something like) batch video transcoding overnight and it will probably over heat and start throttling the CPU to protect itself. The same could be said of any m-ITX board though.
So somewhere in that spectrum (excellent airflow/light useage; poor airflow/extreme useage) lies what you're going to do.