Here I am! Lol
I don't believe there is such a thing as ETD, though I have heard of CTD (not sure if it's just a rumour or not, though).
Embers are smaller than neons, but not nearly small enough to fit into a betta's mouth. I prefer them to neons for their nature, too - they are calmer, less nippy and just all round very chilled fish. It makes them perfect to go with slow-moving guys like bettas. They do really well in planted tanks and look absolutely stunning against the green.
If you want to look at rasboras, I'd suggest Espe rasboras instead of harlequin. They look exactly the same, pretty much, but Espes are smaller and have a slighty smaller mark on them. You also have the option of microrasboras such as borasus briggittae and borasus maculata, although these guys, in my experience, are pretty sensitive. All mine and those of one of my very experienced friend died for no apparent reason.