@Felthry i saw a video a few months ago abnout a recently smaller turbojet iirc
and the smaller the turbine the faster bc higher pressure or w/e so
it's not even just like. an exercise in pointlessness, it's the way to increase efficiency, which i think is super cool (i assume you know this too and that may be why you're asking)
@kit of course there's a ton of problems trying to miniaturize one to _that_ small, but you miiiight be able to make a ramjet that small? You can certainly make solid rockets that small; that's what bottle rockets are.