I am unable to resize the Workbench process canvas either horizontally or vertically. I'm using Workbench ES4. Has anyone encountered this and, if so, how did you resolve it? I'm thinking it may be a Flash Player issue. If I figure it out, I'll update this thread.
I have had issues adjusting the horiz width in ES3 and ES4.
I have been able to adjust the swimlane height by clicking the swimlane and setting the property there.
The only reliable way I have found for width is to open the .process file on disk ( outside of WorkBench ), and adjust the size parameters.
These files are XML.
Save the file, and open in WorkBench and you should see the changes.