In Suite 7 when a customer had a requirement for dynamically changing drop down list for whatever reason, we could hook into the module and as part of the restoration, check that we were on edit mode and then do:
global $app_list_strings; $app_list_strings['dropdownname']=array(all my options);
This allows us to change the drop downs dynamically, so for example if some of the items on the dropdown were only ever set by automated system processes we can filter out those items for ordinary users.
Under Suite 8 I am assuming this is no longer the case (for those modules that have been converted), I would be delighted if you could say that it was but am not expecting it to be.
Hopefully this would just be a PHP/Symfony injection but some pointers on where to start would be appreciated.