You can set the fields when you do the search to those you want in the final album. With the current version of Zenphoto you can select which fields (including EXIF/IPTC ones) will be allowed in the search, so there should be no need to modify them later. {also, the named fields is not available to you in 1.2.6!)
So, yes, you should upgrade.
If you really want to edit the dynamic album, everything is stored in the .alb file. You can edit that with a text editor.