Prestashop Core Development (1.7) Expert

I am looking for a programmer with extensive knowledge and experience in Prestashop to solve a problem with 1.7 version. A special understanding of the problem and extensive knowledge in Prestashop Core Development is required. We are migrating a store from 1.6 to 1.7 and we run into a problem to solve: In version 1.6 any currency could be created arbitrarily. But in 1.7 although it allows you to add currencies, it must be associated with a international ISO code that has been imported or existing on PS. We need to modify that behavior so that the user can create any currency arbitrarily that can be associated with a generic ISO code (XXX for example), OR have to allow the user to create any ISO code as well. Ideally, solve the problem through a module, or override, without modifying the sources of prestashop or harcoding. BUT we are open to suggestions of any solution that actually works.