Add .dropboxignore directory to exclude folders without using selective sync

I realize this original topic is 6 years old, but I agree, something like a .gitignore would be incredibly helpful.  I've got an issue where I'm synching game saves on dropbox using symlinks (which works wonderfully, for the most part), but a specific game uses a ".new" directory as some kinda diff check/temporary cache when it autosaves.  Dropbox attempting to synch is messing with the autosave (but not manual save, thankfully), and worse, when I set the directory to Ignored, because it's a temporary directory, the Ignored status goes away every single time the directory is deleted and re-initialized.

Having any sort of pattern matching for exclusion instead would be an incredibly powerful feature.