Alright so, here's my input on the two three current leading choices.
Design Blackscales - While I do like what these guys are going for, I feel like it will definitely wind up having flaws added onto it, all of the aspects are relatively mundane so I can't see them being too hard, but certainly not easy, possibly not normal either. These touch on no field of knowledge we have thus far, which means while we will get a bunch of new knowledge from them, they will also be made more difficult by such. I'd recommend adding a flaw or two to the design at least since that would logically make them less difficult, and probably adding a definition to "tall" because as is we don't know if that's supposed to mean human sized(our current guys are short after all), tall for humans, or taller than a human can possibly be. While this means that better rolls can give us greater results, it also likely makes the roll harder.
Research Dragons - The biggest drawback to this is it doesn't give us a design, merely a bonus to designing something related to dragons. However from this we can go off into designing something like lizardmen soldiers, but why hold back when we could just as easily go for dragon men soldiers that have fire affinity and fire breath, maybe even wings. From this we can also go off into straight up fucking dragons, as elites, champions, or just straight up our main soldiers if we feel like it, a line of large fire-breathing beast flying at you is more than likely a terrifying sight after all. From dragons we can potentially even make fire breath a staple of our forces, and likely spread flight around to give us.
Research MotUD - This shares the drawback from dragons of not giving us a design as it is a research action, however it also has the problem of not providing us any sort of bonus to making an effective front-line fighter, which we currently lack. It does set us up for further work in use of and protection from etching darkness however. The main problem is that I don't see the actual design working out, even with the research, it leaves a good bit of room for obvious weaknesses to be added which should make it a bit easier, but it also tries to do a LOT much of which would lead to it very easily not being worth two actions and however many points if cut out, all that on top of being a CHAMPION, which means that as far as I'm aware we get only one of them and they are likely to be quite a bit harder to design.