Yes, of course! :)
Sorry, I should have been more specific. I meant only the output in the preview window and the export.
Variables would be useful everywhere where you want to use placeholders. E.g. for renting real estate I very often create documents where the first name/last name of a person, the amount of rent, service charges and deposit as well as the date have to be changed in many different places in the text. Normally I always search the document for the last value and replace it with the new one (or I work with placeholders like XXX, YYY,...). With variables, this would be defined and done within a few seconds and very clearly in the first few lines. I wouldn't have to do more than change the variables and click export. This is a lot faster and less error prone than the copy and paste method *haha*.
Another use for me would be source references or a bibliography, which could be clearly placed in the YAML header. Especially if you cite the same author or work several times.
Now that I think about it, maybe my suggestion is actually a bit special and probably not relevant for most users of Deepdwn :)