I don't expect a large limit, but 10 LY is too short to colonise even some of the fringes of the bubble. As the Thargoids discovered, there are even a few inhabited systems within the bubble that don't have any other stars within 10 LY.My only comment on scope is that i don't understand the limitation to the bubble proper... the 10Ly thing is the 10Ly thing... but tbh i see the 10Ly limit staying, and instead FD will cycle Trailblazer megaships to different parts of the galaxy every month or so... and they provide a "temporary start point" for players to expand from, deeper in the galaxy. That way FD can prevent people rushing to some obvious candidates deep in the black.
The comment they made about (paraphrased) "you might want to establish an intermediate colony for easier access to trade goods to build up the rest" only makes sense if it doesn't take you well over a year just to exceed the range of a single FC jump, regardless of the starting point. (Given the massive T/LY/hr efficiency of a FC over anything else at longer ranges, and their substantial laden range, I'm not sure that will ever actually make much sense, of course, at least not until colonisation starts to consider systems on the other side of the core)
I'm not expecting it to be really large, but there are a lot of places really close to the bubble it needs a 20 or 30 LY range to get into at all, and even a 100 LY range would still take a decade to get as far as Beagle Point, and a year just to loosely join up the existing "fringe nebula" settlements around the bubble, which doesn't seem like it's going to encourage a massive rush to deep-space options.