It would be dead easy for the Storj sales team to offer such a customer even free storage on the public network, like 1 PB. If they cannot use it due to legal reasons, it won’t cost them anything. And if the start to use it, it is an invest into the public network.
Also as suggested, it should be dead easy to move data from the Select network to the public network. It should not be required to re-upload the data.
This way, customers could try out the Select network, gain confidence and start moving less critical data to the public network and gain confidence on that too.