So what are Kaguya's wincons again?
All I've heard is BFR, but I doubt that'd even work, and considering Law is faster, his attacks are instantaneous, has precog, a plethora of sensory and prediction abilities, and is tactically superior to Kaguya, him winning is more likely than Kaguay catching him with a portal.
Even with the portal, it's very ooc for her to just BFR people with it. She usually follows people inside. Because of this, it's not considered BFR, just BFC (Battlefield Change), meaning the fight would just go on and Law would win as he'd make sure not t get caught again.