Is setting the document title with braced variable names still supported? I found the following article: https://erpnext.org/docs/user/manual/en/customize-erpnext/document-title
The article indicates you can set the Title Field to a data type and set the “Default” box under display to something like {position_id} for {customer}, then set “View Settings” → “Title Field” to title.
I have done this with {position_id} for {customer} in both the default box and the option box. In both cases the title field just says {position_id} for {customer} directly, the variables are not interpreted.