This kind of idea is a good example of why it’s always important to consider the effect of “friendly enemies” when designing systems for a MMO. The same issues tie into the reason we can’t simply allow war allies to rep each other freely and why we can’t have fleet membership influence war aggression or give higher payouts for FW and bounty kills.
If we allowed corps to transfer structures to their war enemies, you could just war dec yourself from an alt corp (or friendly corp) and use that transfer function to bypass the normal restrictions on transferring structures while at war when a third party tries to attack you for real.