Woulda been nice if the fork had a feature to let you choose inputs to match the inputs in the corresponding transaction on the original chain... Would it protect us to have that feature in Monero?
Well the fork almost certainly isnt going to do that. However it could be done on our end. Monero team could develop a feature to "safely claim XMV by using the same ring signature inputs on both chains when spending an XMR txo". Even that would only be partial solution though. If someone else failed to use this tool and exposed their ring signature input and it was an input in one of your transactions than that would erode your privacy even though you had used the tool yourself.
But your comment inspired me to think of another partial solution. Something I hadn't thought of before. If the feature that you wish the forkers would implement on their chain was instead implemented here on the main chain, any future forkers would be forking software that had the tool that you wish the fork chains had!
Seems like it would require replay protection on any new fork, because you would have to make the transaction on the fork first.
Yea I'm not sure about replay protection. I suppose you could make 2 new wallets one for the fork chain and one for the main chain and send your funds from the fork chain to your new fork wallet and the funds from the main chain to your new main chain wallet. It is possible that some joker could front run you and publish your transaction from one chain on the other chain but you wouldn't be losing your money it would just be an inconvenience that way.