As you may know, I bake a lot, mostly traditional French baguettes. I used to be skeptical that rice flour can possibly work in a baguette, for the exact same reasons above: rice flour has no gluten, it will make the dough more dense, etc. Actually, the assertion I found way back then was that Vietnamese baguettes has mashed cooked rice in them! Mashed cooked rice?! Forget about it, I though. Until I actually experimented with using various percentages of rice flour in my baguettes. The rest is history! I am now a firm believer that yes, it is essential to use mashed cooked rice in Vietnamese baguettes. That results in baguettes with thinner (but still crispy) crust and much lighter crumb, neither of which is achievable with flour-only dough.