Actually, that's not very good advice. It really doesn't need flaps to do what it can do. And it can do adequate square turns quite nicely. That is, if either the pilot knows to fly the airplane, not just yank the handle for the square turns. The Ringmaster has always suffered from having builders set up the elevator so it'll go 90degrees up/down, and then being flown using all that movement. They're often flown that way by beginners.

Rig the linkage so it takes a fair amount of handle to deflect the elevator and the sucker flies great. And makes one fine trainer. Setup the linkage too fast and it's a marginal trainer. And the people saying it isn't good because it doesn't have flaps probably setup theirs too fast.