I don't think you understand STOPOVER, LAYOVER and CONNECTION.
You are allowed one and only one stopover on an itinerary. You are allowed unlimited connections (<24 hours on international itineraries). So if you "use" your stopover in CDG, why do you think you can use another one in PRG (even if a stopover in PRG would be allowed with that routing)?
Huh? The post you quoted clearly states that CDG is a layover (<24 hours), not a stopover.