Limit tx to SegWit1x or 2x chain Given the lack of replay protection when the SegWit2x fork splits off a different chain is there a safe mechanism to broadcast a tx so that it will only be accepted by the 1x or 2x chain nodes? 

If the answer is no would an option be to run both a bitcoin-core and btc1 full node and send coins to myself on the btc1 node. Once that tx is accepted into the SegWit2x block and NOT the 1x block I'd have safely split my coins? If the tx got replayed onto the 1x chain I could try again, hopefully not too many times to avoid fees.
All transactions would be replayable on both chains even after one was confirmed in a block on one chain, because since both chains start with the same UTXO set, the transactions spending those UTXOs are valid on both chains. The only exception is coins mined on each chain after the fork, because those coins will not be valid on the other chain. So that is how you can split your coins, you would need to mix your coins in transactions which use coins mined after the fork, so they are only valid on one chain. In the case of such a split I assume there would be some sort of service launched by the miners on both chains to start mixing people's coins and splitting them

EDIT: Ledger have announced they'll offer a tool to do that, its likely others will too: https://twitter.com/LedgerHQ/status/921730827117096960