Thanks for following up. I'll do without the volume fields and use the default override in the settings menu for the AVI prompt.
While I appreciate that ImgBurn is a GUI based tool, we do find ourselves in a situation where ImgBurn is a better MkIsoFs than MkIsoFs itself. Your tool is more capable and much better maintained. In my case, I was looking for a way to dump ISO 9660 and generate pure UDF disc images as a way to get around the 9660 4 GiB file size limit. The last version of MkIsoFs to support Windows theoretically supported multi-extent files with ISO 9660 level 3 options, but support for that is broken in practice. My first thought was "I bet ImgBurn can do it!" and I was right. =)
In any case, thanks for your continued development. Know that it is appreciated by many.