The difference is, nobody is asking for Franky to be the sole focus of the arc. Or even extra important plot wise.
Just be natural and use the guy that knows most about VP to: give us exposition about the island, give him a panel or two of him tinkering with some VP tech, a panel or two asking VP about XYZ, or even just pick something up and say "this'll be useful for General Franky/the Sunny/Nami/Usopp/me"
That's it.