Interactive grooming splines trick to add guide clumps. Node  that this will work for for the guide node density multiplier and for hand placed guides

First you need your basic groom scene on IGS and both a guide node and a Clump node.

Then you need to link both the guides and the clump together. So IGS knows where to look for the guides points. As there is no connection between the guides and the clumps at this point.  IGS CLUMP is just looking at the hair and direction.

For this we need to use the node editor and connect the Inguide Node to the Clump node.  

First select your IGS groom node and expand in the node editor. Then look for the InGuide_Shape node and the Clump node. 

Ignore the “GUIDE” node, as we need the inGuide_Shape.  Expand them using “3” to see all the options and connect the Out Spline Data to the Input Points.

This will let the Clump node know where to look for the guides. But will not have effect yet

Now you need to select the CLUMP node on the IGS interface, and search at the botton on EXTRA ATTRIBUTES for  

Now everything is connected you will not see any update on your scene, you need to turn OFF and ON the clump system for this to update on viewport.

And we are done you can even change the INGUIDE clump density and will respect it.