In the IK FK Switch Community Discussion, there was a question about bool and float for the driver property. For the parent switch, are there any situations which float is used instead of integer?
Good question K-Chow.
Parent switching and FK/FK switching are very similar but the difference is....
IK/FK switching has 2 sets of controls that the DEF bones switch between.
Parent switching has the same set of controls that switch what they are following.
There is a benefit to having IK/FK switching as a float because you can switch over a few frames to make the switch seamless.
If there are only 2 parent options, you could potentially do the same in some situations. But more often than not you won't be able to.
There could be more than 2 parent options, or one of them might actually control another part of the rig (in the IK/FK switch both sets control the same part...potentially), or blending between the options will give you some really weird results.
So Parent switching works best as a boolean. IK/FK can work as a float.