Inno Setup: conditionally install language files?

I ship 4 or 5 languages with my Windows app
Inno Setup allows me to allow the user to select a language for the installer.
I’d like them to be able to choose which language file is installed, so that anyone in Germany who hates my translated text can choose to have the English version instead.

Its tricky guiding people to deleting the .mo after the install has completed.
So does anyone know how to either:

Present a choice of languages during the install, and install conditionally?
Parse the installer language settings and match that with only one of the .mo files
delete all but one of the .mo files after install completes?

There’s a page in their help docs that talks about custom pages.