Two would probably fit but as the weight would be over 6.5lbs I am SURE we would have an overfire. We do lay them down on their side, sorry I'm being vague about that! We just put it in on its side cause that's pretty much the only way they go in that little box .Sounds like you are on to something. The stove will not burn like a fireplace. It's a very different burning process. Have you tried burning the ecobrick laying down flat? Will two fit in, lying down, with a gap between them?
Do you have any friends that burn wood regularly that would trade or give you a box of known, well seasoned firewood? You may need to resplit it or recut it to fit the Morso, but that would help with the learning curve.
Ummm, I can't think of anyone we know who burns a stove. We have one friend with some fireplaces who has given us a bit of drier wood but we haven't tried it exclusively.