Hello there,
I've come across the following issue when using Google Translate via the MT Enhanced plugin:
Locked inline elements are not included in the translation. Here you see the translation results from Google Translate via MT Enhanced and via the pre-installed plugin:
Since the pre-installed Google Translate plugin does include the locked element, I hope it is also possible with the MT Enhanced plugin. I've tried English>German and German>Spanish so far.
Here is an sdlxliff file with which you can test it:
Can you confirm that this is a general issue? Can you fix it? :-)