Hey @JLD - thanks for following up on this. It has been sometime, but I think what I was running into was the notion that when workflows are executed by a batch process without GUI (e.g., with Windows Task Scheduler), flow variables aren’t reset. In fact, there was a time I caught this when I noticed that the date was still stuck to the date I last opened the GUI, despite the rest of the data being ‘fresher’.
I don’t recall if I tried the flow variable line as a trigger - it is a technique I regularly use now, but not sure if I used it back then. I may have also just been trying to rationalize some nodes.
For that specific problem (getting system timestamp into the workflow) I now use the Java Edit Variable (thanks to @qqilihq help here) and as you suggested the flow variable line to pull it in. Seems to work in batch mode as well.