We speak of 'winning' debates, but really no minds will be changed, by and large. The RE masses will stay ignorant, the FE truthers will stay ignorant as well. We're all too stuck in our beliefs and closed minded to the other side because "they're all idiots. Look at the proof it's obvious we're correct!". So no, flat heads are not admitting they're wrong. Nor are round heads.
However, having a dissenting opinion is good, as it prevents an echo chamber.
Look at the new wave feminism (it is not actually feminism, the values are very different, real feminism is actually quite respectable). They're all about echo chambers, and they've got all sorts of crazy ideas, because no one is there to give them a reality check. They're talking about how "men are pigs and don't have emotions besides uncontrllable rapist lust and all attempts at romance are just weakening the woman's guard so they can rape them, and all men need to be euthanized immeditely" etc. It's untrue, but no one's there to stop them.
Keep it real my flat dudes.
Fun fact: some quick online shopping can get you a high altitude balloon and a wireless camcorder for less than $160. Prove those round/flat earthers wrong for less!