Executive Summary: If in doubt, go with the Theymos default. If exporting/selling BTC is a hassle and you trust your bank and it claims it would handle the split like giving you both coins: consider also "doing nothing" i.e. no moving the coins.
Quite a winded post that in the end justifies the argument it was supposed to rebut.
LOL. Posts that put cognitive load on the reader are considered "winded". I get that.
It offered a different perspective to withdrawing your BTC funds from exchanges.
There is neither justification nor rebuttal.
Actually some exchanges are already documenting they will handle the case as did Kraken handle the case in my ETH/ETC example.
In these cases, one might actually go against the "Theymos default".