Targeted localized string directories with drop-down versions

Question

I have an application with two options (whitelabel), implemented as two separate goals. These two applications are localized and may have slightly different user-oriented strings, depending on the purpose.

I split the file Localized.stringsinto the shared part and the target parts. Each target compiles a common Localized.stringswith common lines and one of the options Target.strings.

Then I can select either NSLocalizedString(), or NSLocalizedStringFromTable()to find the desired line or even combine them and first look at the line with a specific type, if not find, return to the default directory.

So far so good.

The stumbling block is the IB file, because I can only have one line file in the / xib storyboard, I cannot include options for each purpose.

I looked at a number of build-time hackers (custom scripts to combine string files), but I want to know if there is a better way around this.

Ideally, I would like to redefine the string search mechanism so that it supports multiple line directories and first looks in a directory that focuses on specific actions.