The only reason we have titles in the first place, is to support characters and longer strings that are not possible to have in the filename. So basically, this is just like an alias for the filename ... Just like a file always has a name, so will the title. You can choose to display it or not, but the name will always exist ...
So you want the title available only in a few folders? Then use folder parameters to allow title to display in some folders ...
https://www.photo.gallery/documentation/folder-parameters/