Future Cinderellas

That would certainly do some stumping !
But my first thought was what an awful, awful stamp that is. Gross

I'll have to look around for some of these 'Cinderellas'.

Londonbus1

I think this is a modern Cinderella, but can't tell. Any idea on the date, country or purpose?

I found another "older" potential Cinderella. Let's see if someone can figure this one out. Hint ... you can see the sideways watermark.

Here are a few more examples. The first set has Cindys on the Top, while the second set has Cindys to the Right.

I would say that these nice Cindys are not true Cinderellas, even if they are found seaparated. They WERE issued by a governmental post; they were intended for postal and philatelic use, INDIRECTLY, by their original status of tabs (se-tenant labels) associated with the real stamps.
A true Cinderella is independent and without postal value from the get-go.
I would call the Ceskoslovensko Cindys as pseudo-Cinderellas, once they get separated. They had the role to complement/augment/beautify the real stamps.

I agree 100% with DC3 statements. May be I'm somewhat old-fashioned, but I enjoy late XIX and early XX centuries cinderellas.
By the way, the leaves' cinderella, looks French to me.

Thank you, Cursus. Yes, that leafy Cindy could be from any francophone country or territory.