On the main topic of the post, I've been assuming, without having put too much thought into it, that slower economic growth is good for eventually getting FAI.

Here's an attempt to verbalize why I think this, which is a bit different from Eliezer's argument (which I also buy to some extent). First I think UFAI is much easier than FAI and we are putting more resources into the former than the latter. To put this into numbers for clarity, let's say UFAI takes 1000 units of work, and FAI takes 2000 units of work, and we're currently putting 10 units of work into UFAI per year, and only 1 unit of work per year into FAI. If we had a completely stagnant economy, with 0% growth, we'd have 100 years to do something about this, or for something to happen to change this, before it's too late. If the economy was instead growing at 5% per year, and this increased both UFAI and FAI work by 5% per year, the window of time "for something to happen" shrinks to about 35 years. The economic growth might increase the probability per year of "something happening" but it doesn't seem like it would be enough to compensate for the shortened timeline.