Houdini's hair clump node looks at the custom clump curve prim id when assigning the clumpid attr to guides. Right? Hair clump node uses the same integer as the id attr when assigning clumpid integers.. or does it?...

I'm trying to change the id attr on a set of curves that are plugged into custom clump input and I'd like the clumpid that results from this work to match any changes I make to this mentioned id attribute but the clump node doesn't seem to update. How is the clumpid attr generated actually?

Moreover, is it possible to tell houdini's hair clump node to look at a specific attribute when assigning clumps? This would be nice and would open up some opportunities to generate clump shapes with painted maps like xgen.