I tried Everything I can humanly think of!!!
If you think about it Eloqua needs to distinguish between a Decision Step in one campaign vs the other and {InstanceID} is the same for each decision step. So when I reference them I do not see how InstanceID alone is all that is needed.
{{Asset[22].DecisionInstance(6dc71bc088874768a026720c01775ce2)}}
{{Campaign[22].DecisionInstance(6dc71bc088874768a02c720601775ce2)}}
{{Campaign[22].DecisionInstance[6dc71bc088874768a02c720601775ce2]}}
{{Campaign[22].DecisionInstance[6dc71bc088874768a02c720601775ce2].Id}}