Qb6 can also be played in some lines Nxd4 Qxd4 system when the queen retreats to e3 (to excange queens at get good play dispite double pawns in some side line), but overall Qb6 is very rare in Marocy structures.

...Qb6 is never played against a Maroczy pawn structure. There might be some exceptions. But I don't recall anyone at this time.
In the hyper accelrated dragon I guess I have seen something like that. After 1.e4 c5 2.Nf3 g6 3.c4 Bg7 4.d4.

I don't have my books right now. But if I am not wrong options could be:

a)4...Qb6
b)4...cxd4 5.Nxd4, and here if you want 5...Qb6
c)4...Qa5+

This is a bit of a crossover question.
In the KID Saemisch it seems that Black can transpose to the Marozcy, though it never seems to occur. I'm interested in this for two reasons, because I'm considering this as white but also beacuse I may face this when playing the accel dragon.
The moves are 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3 0-0 6.Be3 c5 7.Nge2 cxd4 8.Nxd4

I always thought that an early f3 was faced with ..Qb6.

I've searched though quite a few games and no particular line stands out.
Some fairly notable people have had this position as white from various move orders.
In a lot of these games there seems to be a transposition into one of the more recognized Maroczy positions (ie; Gurginidze or classical).

These move order shifts are so numerous I can't work them all out!
Can white guarantee transposing to a decent line with an early f3? (ie; no dangerous deviations).

The fact that from the KID move order black doesn't always take them into the Marozcy must indicate that there isn't a really decent black variation (or refutation).

The only thing I can think of is if there is a line where f4 is more approriate - but I'm not sure if white has to go into those lines.

I'm curious?!