The newer bios also set lower voltages(mem io/sa etc) on z590 Apex and boot/train better if you are into mem OC.
I would take the SP # with a grain of salt. I have a SP55 and SP85 11900k and they both clock the same. The big difference is 53 voltage is different, I think this heavily influences SP rating. But when manual OC they top out the same.
It is not like a sp55 will perform less than a sp99. SP 99 should just need less voltage. The newer bios use newer microcode so the SP is suppose to be more accurate.