@stloyd @pjedrzejewski I can't :'(. Alice doesn't allow me to do something like 
``` yaml
Sylius\Bundle\AddressingBundle\Model\ZoneMemberCountry:
    Sylius.ZoneMember.EU.{<?=$myloader->getProvider('country')->myFunctionToGetEuCountriesAsList()?>}:
```

I see only 3 solutions for countries and zones : 
1. let this ugly code for now
2. load countries by hand in the countries.yml and zones.yml files
3. go back to old way for countries and zones