Its impossible to that naruto could use kurama sage mode for now.
Why? because sage mode require balance type of physical, spiritual, nature energy.
Mean if naruto is in kurama mode, it will be more spiritual than physical, to make it quite impossible to balance it enough to draw nature energy outside.
Mean there is only one way, where naruto have to teach kurama how the sage mode work.
Once kurama, learned that, kurama can balance its physical and spiritual,
Sage mode become stronger when you have stronger balance type of spiritual and physical. Mean the greater is your spiritual and physical power in your body, the greater nature energy you can draw from outside.
Naruto without kurama mode
spiritual power (1000) + physical power (1000) = drawn nature energy (1000)
Battle Ratting will be 3000
Naruto in kurama mode
spiritual power (10000) + physical power (1000) = drawn nature energy (1000)
Battle rating will be still 3000. mean naruto were stronger using his kurama mode than sage mode.
These why he rather use kurama mode rather than sage mode.
Naruto switch with kurama, to let kurama control his body.
spiritual power (10000) + physical power (10000) = drawn nature energy (10000)
Battle ratting 30000. Awesome amount but require kurama to learn how the sage mode work.
