So looking it over, i have noticed a lot of more similarities/connections between the Kage Kage no Mi, and the magical power system the Five Elders and presumably Imu uses alongside their respective devil fruits.
Arguably the most iconic, and definitly the most usefull of the magical powers they have hoarded for themselves, is thei seeming total immortality, allowing them to regenerate from any wound by essentially resetting themselves back to their default state.
However, we have seen something similar before related to the Kage Kage no Mi.
When stripped of their shadows, several of the victorious straw-hats and allies are exposed to the sun and disintegrate...
only to immediatly regenerate back like nothing happened once their shadows returned, with Sanji and Robin speculating that it was due to their shadows "Forcing" their bodies to match their shadows.
Regardless though obviously less directly controlled by the participants, this visually seems to be very similarily to the aforementioned five elders regeneration above, with similar connections to the element of shadows.
The five elders have access to a form of teleportation through pentagrams that funtions like a summoning. And when summoned, they are in a state that resembles that of of living shadows.
meanwhile, Moria has his own teleportation that allows him to switch places with his detached shadow, summoning it to take his physical place, while he swaps with it, with the inbetween state resembling that of living shadows.
Also interestingly, not only is Moria set to make a comeback in the final arc of the story despite seemingly having made no progress or growth in his combat ability since thriller bark, but Imu's very first action in this series was when he/she ordered Doffy to kill Moria off after the war, supposedly for being too weak, but probably more due to wanting to get ridd of one of the two shadow/darkness devil fruit users at the moment.
And while obviously a lot of the five elders powers are their own, or comes from their own devil fruits, it's also clear that wheter they are empowered by Imu's powers(wheter it be actual magic or a devil fruit), or they merely draw from the same powerset, their role in relation to Imu ver heavily resembles how Moria calls upon his own shadow to fight his battles for him despite being a rather powerfull figure in his own right, but not capitalizing on it to make full use of his powers.
And finally contrasting Moria and Imu, is that there is a unique language Quirk to the Kage Kage no Mi. Every other devil fruit in the series that makes the user labled as a specific kind of being "Rubber man", "magma man", "insert animal here Man", etc-
But not the Kage Kage no mi.
Rather than being a "shadow man" as one might expect, the description of the Kage Kage no Mi, one instead becomes described under the term "Master of Shadows".
Not special on it's own, but it is the ONLY devil fruit in the entire series that is described this way. It could be a coincidence, but it could also be a specific detail on oda's part to set it up against Imu's similar powers and role in the story.