the slab in question:
based on the footers, location, and all that, this is roughly the location that has currently been concreted (red outline).
not a big portion, but it’s at least become a decent anchor for the scale & location of the area. there’s a lot of footers around, though, most currently left unpoured apart from ones which I believe are for the inclined turntable & above zig-zags (those seen within the black braced off area in the 2nd pic). I think (or, hope) these are separately poured only due to queue path seemingly going underneath this section, and not because it’s indicative of that area being outdoors.