Hi,
We've started some work regarding that but we still need some time to work on that and completely separate the shipping and billing addresses.
It won't be with the next version of HikaShop, but we hope to be able to add that with the one after.
Next version, that we will release in a bit, will allow you to have the entered billing address forced without being able to modify it and the shipping address with the edition/modification interface. So you'll already be able to do that without having to separate the billing and shipping addresses.