How to ID shadow link to ObjectID or renderID or whatever ID link to object

Hello,
Does somebody have an idea how I can create a shadow ID per object?
I would like to easily select the shadow of each object independently (not all shadow at once). Or should I keep going the manual way of one render per object and then composite the image again.
Thanks

It won’t come around until the guys have full LPE expressions which I think are in progress? Prepare yourself for a lot of render passes :smile: