Hi thomas,

If you want to make an entity translatable you have anyway to modify its code.
First to set the locale for gedmo listener and then to defined exactly which fields are translatable or not
For example you can translate the name but not the position, enabled...

So you have to modify the code in all case so it's ok to add an interface.

For the on demand translation, this is made with configuration as You did a great job with the admin extension configuration you can register the extension only for some entities...

So this code fits your needs