You can increase your PBO limits PPT 300, TDC 230, EDC 230. Alternatively you could increase them to max. Buildzoid had stated that the numbers I listed were better on Zen2, but I have no idea if it really matters, especially on your hardware. IMHO it's mostly academic as those numbers are effectively much higher than anything the CPU will pull. You can see in your second screenshot you're maxing out on TDC and EDC. You can also try adjusting the scalar. I would do some more searches about optimizing PBO for your specific chip.
I don't think you need to change your voltages other than DRAM. For memory it's important to keep your FCLK and DRAM matched (DRAM is listed as 2x the speed as FCLK because its double data rate). Looks like you're doing that here. The DRAM calculator can be a good starting point, but it's not gospel, every system is different, it works for some and not for others. If you're chasing fractions of a percent in performance than it's worth it to really sit down and tweak your timings, otherwise it's not super necessary.
