Using Client activity in Report Dataset Transformer workflow

Hi. I have a Rpt dataset transformer WF, which I'd like to modify slightly. There are some layerIDs (for map service layers) hard coded into the WF and I'd like to use the Get Map Service Info activity (client activity) to dynamically get the IDs. The entire WF is inside a Server Scope activity which means no client acivities are permissible. It seems this is a requirement for these transformer WFs. Is there a work-around for this?

 

I have tried putting the entire workflow into a new sequence and adding the GMSI activity there. I have also tried putting that activity into a separate WF and using the reference workflow activity. Both of these fail.

 

Thanks