Thanks again. I looked at it but working with advertising banners it’s a bit specific. I found this, but I can’t use a language selector in a banner, each piece will be sent displaying already one language in their own market.
The rest of the discussion is interesting but I really don’t have the time to learn coding javascript at the required level, it all really looks complicated. I wanted to use HTML5 with no conding and so far I had to learn to use actions to make the banner loop 3 times and stop which is pretty standard requirement in ads 
For the time being I just tried going ahead and copy documents per language and translate them secuentially as I do in Photoshop, more or less.
I have to try creating symbols per each element (Claims, prices, discounts, other texts…) so that would allow me to translate quicker those elements across the document, one per language, in all scenes.
Creating one document and all the languages in it, hiding or showing dozens of layers in a same scene could work. But seems a bit complicated to handle.
All in all, I wish there was a simpler solution. It’s hard to believe it’s so hard to manage HTML5 and localizations nowadays. Hundreds of people must be in my very situation creating ad campaigns for many international markets on a daily basis. How do they do it?
Luckily the copy with animations function works fantastically! This helps me save a lot of time to make the different sizes
Like anything, practice is everything so eventually I’ll find my way around this and much better than using Google Web Designer, I’m sure.