So from testing,
I have changed the variable to the ECR template from <ECR_Title> to <Title>. Template is an XLSX. <Title> is set as summary and custom property attribute in the variable manager (EDPM). Also have set the <Drawing_Title> attribute for the <title>. When I create the file, I'll find the data in the title custom property and the associated cell. The document property is unchanged still says template title. If I change it, it will update here, not in the customs tab, but will update the data card. If I change it in the data card, I have no change in the file, and have a new custom property as Drawing_Title.
The more I play with this, the more I think I'm going to have to run a script through my vault to fix this...
Anyone has had any luck with this kind of issue?