Adui
Maybe there are restrictions as well? Could that is the reason Cecilia can't act on much. Maybe the orders from an edicts creator are absolute, and followers have follow it to the letter. Maybe that is why the creator of edict of Samsara didn't say anything about Noah. If he sat still and did nothing he would gain a completely broken follower. But if Sanguine Aggregation is what I think it is then Noah will completely bypass this restriction by combining all his True Bloodlines into one and strip himself of the so called follower status. Orders to not interfere with the Primordial Empire? Sorry bud, the Sanguine Emperor is no one's follower!
The Champions of Reality, through their Systems, are bound to and within their Reality. The higher Existences are unique and exist outside the bounds of reality, easily traversing the multiple Realities. The Primordials may be bound by their bloodline the way Oathkeeper bound the Hegemons of their Cosmos. I think the benefits of a Higher Being is contingent upon the Bloodlines and Edict Flames that catalyzed their elevation. The fact that Noah used a Quasi Insuperable Edict of which he is the Architect to Ascend his state of existence grants much more than ascending with a Greater Edict, not to even consider ascending with just a Lesser Edict, that one is not the Architect of. I think a Higher Existence’s Origin doesn’t use Mana, but becomes the Essence of Reality. The purpose behind the Champions is a watch dog to guard the dimension, but the Primordials gain something from the Realities they oversee that is necessary to rise above the Cosmic Filament stage.
Also, to add on to Iwantasystem's ideas of multiple realities and timelines, as well as his idea of other entities on the same level as Primordials, there also could be a bunch of interesting things on a smaller scale, such as with the individual timelines. Because according to the whims of the presiding Primordial, Champion, and the starting condition of the timeline they are in, things could be vastly different than Noah Osmont's reality. In one, someone could have elevated technology to the level of edicts. In another, they might of taken the path of the mage. Who knows, someone could have taken the elemental laws and forced them to be at the same level as greater edicts just because they could, and they had all the time in the world. We literally have universes made entirely of water and fire, so the possibilities are endless.
I won't comment on the perks, but I think there should be a whole other world. Like, there are not only different primordial empires ruling over different branches of timelines, creating more timelines and restricting the end of realities, but there are also other species of higher existences that should be there and have their own empires (like an altered version of the dragon, elves, etc.). And there are multiple original timelines that all start and end at the same point, but no one knows what those points are.
Higher existences should fully embody their origins. They can take any shape they wish. Their blood is an expression of the essence of Reality; in the same way that Primordial essence works with Ruination - Reality works with the Blood of Higher Existences. As a result the bodies of shapes they can take are manufactured whole cloth, at will, physical damage means nothing to them. Their powers take the form of concepts.