If your buffer size in Ableton is 256 or less you should be hearing very managable latency. Some need 128 or 64 to feel right, but 256 is probably low enough. If you still hear latency with 128 check your plugins in Ableton – youre hearing delay compensation probably. There are a lot of plugins that add latency – specifically anything that uses FFT transforms which means a lot of high end EQs which use FFT to eliminate phase issues.

Anyway – in a new session with 128 sample buffer you shouldn’t hear latency.

I play Kontakt and Pianoteq pianos live in the DAW all the time… just be mindful of PDC.