A single control anchored in world space, with a switchable space attribute so it can follow its parent joint, world, or any joint you add.
What it does
One control, switchable space
AdvancedFK builds one control for one joint, much like SimpleFK, but instead of parenting under an ancestor control it sits in world space and carries a switchable space attribute.
Pick a target in Properties (its skeleton parent, world, or any joint you add) and the control follows that space.
When to use it
Anything that changes parent mid-shot
The parent changes
The control needs to switch spaces during a shot.
SimpleFK
If the control only ever needs one parent; the plainer, cheaper choice.
Per-target marking menu
The marking menu adds a Match to Space and a Switch to Space entry per target you've added, on top of the usual Zero All / Zero Translates set.
One joint per instance
Selecting zero or several fails before the component can be added.
Names come from the joint
The control's name comes from the joint's short name, so two joints sharing a short name collide on control naming.