Trade, that's only true if there is an escrow agreement in place. There isn't one that ASX and ISX have agreed to. There's a big disconnect between the escrow ASX want, and the escrow ISX have offered.
I have mentioned numerous times that the escrow agreement is key to get trading again - especially due to the reasons you've highlighted. Without one, we're dead in the water, and simply won't trade - irrespective of which exchange.