When looking at deploying this I wanted to delpoy it to a multi-user environment and ended up changing the way it parses from the configuration file such that instead of changing the field if it equalled %username% it changed all references to %username% by using
sConf = sConf.replace('%username%', getpass.getuser ())
I would suggest building this into your next release.
Thank you very much for your feedback,
this feature was planned in the next release, but due to unexpected load of work I had to delay its release. Your request will be taken into account for the next release :-)
Code implemented into the next release. And this variable now works in any field. All future special variables will be implemented dynamically in a similar manner.