This could very well be a Franky heavy arc, with him having the biggest connection to Vegapunk known so far, with spending two years on his home island and in his old lab.
If he gets an upgrade what would you like to see from it? Stronger weapons could be nice too see, and maybe partial transformations with his vehicles and a new General Franky power up.
Possibly even a Combination General Franky and Thousand Sunny Super megazord.
Stronger lasers.
Seastone bullets/armor/sword.
More efficient Cola usage (Franky is actually really powerful, it's just his strength being tied to cola that makes him vulnerable).
My ideal dream would be Franky getting multiple Devil Fruits for different parts of his body: Strong Right becomes a stretchable anaconda, Weapons Left becomes a fire breathing dragon, etc.
Finally, a fucking Franky arc.