Net positive energy is indeed kind of arbitrary. Hitting Q=1.1 is not substantially more difficult than hitting Q=0.9. There's no barrier or even minor bump to get over, it's a continuous scale of linearly increasing difficulty, and even that scale can vary a lot depending on the specifics.

A comparison I might make as an aircraft geek is that it's not substantially more difficult to make an engine that produces 1.1 tonnes of thrust than one that makes 0.9 tonnes of thrust. As it happens, that's pretty damn close to the thrust numbers of the first and second production models of the world's first fighter jet engine; the Jumo 004.

However, the reason it's significant is that if we suppose that the engine in question weighed exactly one tonne, then the first model would be incapable of lifting it's own weight off the ground, while the second model could. Increasing the thrust by that small amount is relatively trivial and mundane, but the consequences of crossing that 1:1 threshold are profound.

(As it happens the Jumo 004 actually only weighed about 0.75 tonnes, so both versions could in fact lift their own weight off the ground)