You need to start a dialog with Leanthar and EdTheKet on this if you're serious about it. Anything that anyone else will tell you will bet at best incomplete and at worst inaccurate.
So if you have any further speculations or inquiries regarding the RDD class, you need to have the conversation with Leanthar and/or EdTheKet, because nothing anyone else says here is going to make any difference whatsoever.
This became a long thread!I looked at the text in question and can see where it doesn't match how we're portraying the extent of the number of people speaking draconic, it being taught and all that.I'll have it remedied in the near future. However, there's also some points I have to talk to Leanthar about and he's out until the end of the week so I'll get back to this later and cover it all in one go (I hope, if not you're all vocal enough to ask ).