Hello, while the Wayland trackpad gestures indeed hardcoded, overriding and then disabling those gestures is possible using this third-party script.
IIRC, setting a gesture’s action: none will effectively disable that gesture, but I can’t find an example in the docs. I also see it has complications in Kwin 6.4 requiring a small workaround.
As the developer of the effect notes below, gestures can be disabled by setting up a small configuration, minus the actions property.
Hope this helps while they continue to figure out a modular approach!