Xcode 13 beta 3 - should it create Localizable.strings file for the base languge?

I wanted to know if I am doing something fundamentally wrong with Xcode 13 beta 3, with respect to localisation.

I'm using the new compiler support to extract strings for localisation then exporting -> translating -> importing via the .xcloc files. All this works nicely, aside from one problem...

I'm having difficulty getting it to create the initial Localizable.strings file in the development language, i.e. en in my case. When I try and import the relevant en.xcloc file nothing happens. I can import other languages without problem.

Here are the steps I am taking:

1. Write some basic code with one piece of text that can be localised
2. Select Product -> Export Localisations... and choose English - Development Language

Correctly creates en.xcloc file - contents as expected, picking up the text to be localised.

1. Select Product -> Import Localisations... and re-import the english en.xcloc file

This does nothing. So I try the following:

1. Go to Project's file -> Info tab and add a new language, say (Fr)
2. Select Product -> Export Localisations... and choose English - Development Language and French options
3. Open fr.xcloc file and add translations required
4. Come back to Xcode and import fr.xcloc file
5. Now the Localizable.strings file appears - it is of course the French version
6. Importing the en.xcloc file still does nothing
7. If I open up the file inspector on the right, I can click to add an English version, but it simply copies the French version (which causes lots of other issues)...

Any ideas?