I wonder if you can use paragraph styles to the same effect? I tried to make a paragraph style and set that to “Delete text of this style” but the paragraph itself was still present in the compile output. Maybe I did something wrong? (I tried some days ago and I deleted all my styles I used for it meanwhile.)
In theory I would like to have character styles I can use to conditional suppress text as well as paragraph styles. My text was a mix of different strings within paragraphs but also whole paragraphs which should be conditionally suppressed independently.
For the time being I switched to whole folders/documents being different and the custom metadata/collections approach you explained here.