itch.io

I don't think there's a built-in feature that does what you're asking, but by modifying this function I think I was able to get the behavior you're asking for. It makes it so inputs are always in cardinal directions unless you're pushing more than one direction.

mv3d.getInputDirection=function(){
    let dir = mv3d.DIR8MOVE ? Input.dir8 : Input.dir4;
    let yaw = mv3d.blendCameraYaw.currentValue();
    yaw=Math.round(yaw/90)*90;
    return mv3d.transformDirection(dir,yaw);
}

You can load the script as a plugin after mv3d.

Qmovement is also available as an alternative to Altimit movement, if you want to try that.