:dhe will be able to extend his sage mode for more peroid
I hope so.
But in Sage Mode to attain this state, there should be a balance between physical, spiritual & natural energies thus forming a new Chakra (Sage Chakra) which drastically increase the user's ninjutsu, genjutsu, and taijutsu.
To increase those Sage Chakra reserves, Naruto needs to increase also his physical and spiritual energy capacities.
If my understanding is correct, what Naruto obtained lately is "not" another form of energy to increase his "energy reserve",
but already a Chakra. This is the Kyubi Chakra (formed from the Kyubis own physical & spiritual energy, and not Naruto's own which he previously balanced with the nature's energy. And I don't think it could be broken down into physical and spiritual forms and be distributed to Naruto's, since it already have the entity of the Nine Tailed Beast. Naruto could only use or borrow it's inherit power or abilities which is naturally used by the Kyubi.
Unless there's a crash course Sage Mode training for the Kyubi to learn to balance his own. And develop additional Sage chakra in addition with Naruto's.
I think, the most significant effect to Naruto with regards to his sage chakra, is that he can sense and gather natural energy much quicker and more efficient meaning less standby time before entering the sage mode.