Had Gogeta used the Kaio-Ken, he may have even been able to win. While not explicitly canon material, Dragon Ball Super Heroes has outright confirmed that Goku's fused forms can perform the Kaio ...

Kaioken increases power but poses risks like exhaustion due to intense ki control. Only Goku has mastered Kaioken, using up to x20 but never combining it with Super Saiyan. Combining Kaioken with ...