eth to beth, then beth to eth

So on binance you can swap your eth to beth (1 eth≈1.2 beth) and at eth2.0 staking they say "you can swap your beth back to eth after the completion of the first phase. Please note that you will receive eth equal to your beth holdings at the time of the swap." So my qusetion is, can I swap my eth for 10-20% more beth and after the merge I get 10-20% more eth than my initial eth holding before swapping to beth