Pass attribute values to a parameter for use by other transformers/workspaces

I recently wanted to use the maximum value of an attribute on one table as the start value of the counter on another table. To do this i have to calculate the value then use an attribute creator on each table and a feature merger to then calculate the new counter value

I would have been much neater and simpler if i could have passed the value to a parameter that the counter could use as the start value.