Is there a way to use light guides/play assist in Ableton piano roll without having Komplete kontrol as the midi instrument?
At the moment you can't as all the smart stuff is built into Komplete Kontrol. It's being added to the standalone keyboard at some point, but there are no guaranteed timescales at the moment.
There's a discussion about it here - Kontrol 2024 outlook: what was, what now, what next? — Community (native-instruments.com)
I don't think you can do this, however there is a great N.I. video on YT that may help with Komplete Kontrol.
How to use everything in KOMPLETE KONTROL software | Native Instruments (youtube.com)
Brian explains all you need to know.
I would specify that it will be added onboard only to MK3 models, not to previous ones (that don’t have the technology to host it)