Honnestly I don’t see a big advantage here.
Yes, it is not the best situation to share the genesis block with Litecoin, but things are as they are.The risk is much higher than the possible advantage.
At the end exchanges accept coins that are traded at high rate and give revenues to them.
Let’s think about ways to enhance the acceptance of Feathercoin instead of thinking about a kind of Russian roulette to replace the genesis block