Wow! That's stunning, schemas have been around for over a decade. For the DAL to always assume the schema is the same... no words.

So... what's the recommend way(s) to workaround this limitation when the SPs that must be called are not in the default DNN schema (typically "dbo")?

"I am well aware of Schemas being introduced to SQL Server in Version 2005"... I know you are Sebastian, but DNN acts like its not, hence the problem. DNN still after a decade treats schemas like a hindrance instead of a help. Use of schemas for organizational and security purposes is now a standard with many clients including us, subsequently it's very significant in this case as it requires me to implement a workaround to use DNN.  Hence my question about a doing just that. 

Xmod Pro is a great example where we use its modules to call SPs in other schemas all the time. It's my understanding it uses the DAL so there must be a workaround.

So you don't have a recommendation for working around the limitation other than violating our design specifications?