Sheet Index Custom Sheet Properties

So I'm working on ways to automate my sheet creation process as much as possible. Often, we will have multiple designers, drafters, and specialists working on various components or sheets of a bridge plan set. Sometimes our plan sets can be upwards of 100 or more pages as well. Rather than have someone enter this information on each sheet individually, I was looking for a solution that would allow a user to select the sheets they need to modify from a sheet index and update that selected group in the properties dialogue. One of the things I found that works well for this is adding custom SHEET properties in the "Manage Sheet Index" window. Once those are associated they can be selected individually, or as a group of sheets from the sheet index, and updated as I had mentioned. It allows for some level of automation while maintaining each sheet as an independent entity.

I have set up similar custom properties under the "Index" and "Folder" tabs of this menu for things such as project title, Project No., etc. I then used text fields in the titleblock of my sheet to reference these properties.

Here's where I have problems with this, and am hoping there's some help. In order for a sheet seed to function properly, it should not be tied to any one workspace or workset. and it cannot be part of an existing Sheet index. So I remove it from the index. When I create a new sheet from that seed and add it to to a sheet index with these properties, the properties that are tied to a "sheet index" or "Sheet Index Folder" will re-establish, but the custom sheet properties will not, and the link remains broken.

Looking at the drop downs in the text field editor, there are specific options for Sheet index and Sheet Index Folder, but nothing for Sheet properties. Those reside under "Model Properties".

I feel that's where this breaks. It would make more sense to have sheet properties be a selectable category on it's own. I also understand that this functionality works better in ProjectWise, but the my office has yet to receive a functional test server so we are trying to make something that functions regardless of PW. I feel like the intent is there, but the execution needs some refinement. Is this a known issue or am I the only one that has even thought of trying things this way? I would also like to know if there's another way to accomplish what I am trying to here? Any help would be greatly appreciated.