I’ve made allusions to this before, but I truly believe that Franky picked up A LOT of knowledge from his stint in Vegapunk’s homeland during the timeskip. Although it was said in Water 7 that his research with Devil Fruits was then-recently completed, I don’t see any reason why he wouldn’t have any early notes stashed in that lab Franky crashed.
To that end, I like to think he learned a few things about the true nature of how DF powers are released and controlled...if this is true, he could come up with some way (likely by way of a wacky contraption of his own design) to either neutralize or enhance the users who consume those fruits. Whether this means helping his captain awaken the Gomu Gomu no Mi or simply counteracting Kaido’s abilities at a crucial moment, he could end up turning the tide of the battle if and when things get bad.
As far as how such a thing would work...I don’t fuckin’ know, I’m not some stupid science bitch like Vegapunk
