Short answer: Yes it does
Long answer:
At work I'm passing parameters in request (DataImportHandler: Accessing request parameters) with default values set in handler (solrconfig.xml)
To sum up:
You can do use something like that in data-config.xml
${dataimporter.request.your_variable}
With request:
/dataimport&command=delta-import&clean=false&commit=true&your_variable=123