There are also incidents where they have not, such as this one. Why not use common sense and get down out of the way.
Several years ago I was flying, by invitation is at a similar event. I had a dedicated spotter with me, and there was an airboss with radio contact for the FS operations. A pilot decided it would be fun to divert from the runway and fly over the R/C crowd which was about 500 yeards from the active runway. I was flying a large scale P-47. The airplane was making its approach just as instructed, then suddenly turned right and headed in our direction. I was at about the same altitude as the Cessna, which by the way was carrying several children for an EAA Young Eagles flight. I dove for the ground, and immediately landed. Luckily my plane was not dmaged, but I did not think about that in the instant it happened. The first thing that went thru my mind was I DID NOT WANT TO HIT THAT FULL SCALE plane, irregardless of who would have been at fault. After he landed the airboss gave him an ear full, but I decided right then that at no time do you fully know the intention of the FS plane in the area, and they may or may not see you. Most FS pilots consider these to be toys (which they are), but they do not associate the size and power of these models, and realize the danger. They always have the right of way, and if you are operating in the area with them, you had better be prepared to either ditch your plane or land immediately if you do not know what they are doing.