Against Blackbeard, I would expect no less tbh unless Oda remembers to give Kizaru haki again and gives him something like Kuzan being a boxing specialist. Something kick related Sanji style maybe? He did show that defense vs Luffy though...
But yeah I'd still give blackbeard the upper hand, not even the fastest thing in existence, light itself can escape a black hole....
I really wanted to see Kizaru vs Blackbeard but it would probs end in Kizarus death or capture unless he can escape or be saved somehow.