I wouldn't dare use this to prevent replaying on my real Bitcoins. If Bitcoin would accept this in the future, your transactions can still be replayed.
Bitcoin accepts this already. I think what he meant is to create a Bitcoin transaction with OP_RETURN (>83 bytes) so that it cannot be replayed on the Bitcoin Knots chain. (Then you move your Knots with a transaction you verify that is invalid on Bitcoin.)
Yeah, that's what i meant. It seems there's no way to move Bitcoin first, before moving eCash, unless you have UTXO that only exist on Bitcoin chain (as stated by @DaveF).
The last one, BLuke, was getting pumped but that excitement only lasted for like a day or two! They couldn't keep it up enough to incentivize claiming the airdrop

Which is probably intentionally. If they implement real replay protection that protect owner coin on both chain, more people would sell their BTCB2 coin and further crash its price.