Is there anyway to have a Reaction trigger when you run the Update command on a product? Or is there some other way of achieving the same thing?

In CATIA V5 you can create a Reaction at the product level, set the source type to "Selection", select the product and set the event to "Update". The reaction will now trigger whenever the product updates (and even when instances are added and removed from the product).

But in 3DEX CATIA, when you attempt to do the same thing, the "Update" event is not available. Setting the source type to "Owner" doesn't work either because the Owner is (as far as I can see) the Relations node, not the product itself.