Seeing how the difference between rank 9 SIF and rank 10 SIF is only that dao marks conflict can be switched on and off at will in precise situations (making the user have both extreme defense via dao marks conflicting when needed extreme healing speed via not conflicting when needed.)
And not Needing to consume immortal apertures of your rank periodically... I think it's mainly about removing some drawback/ limitation of the rank 9 version and giving some moderate boost in power.
Same with how rank 9 version of a heaven path gu (fate gu) controls only certainty, but rank 10 version (destiny gu) controls both certainty and uncertainty, basically making you have complete control over the gu world. Same effect, just in higher quality
Transmigrated anywhere other than central continent BTW.. 4 thousand years before FY.