I have a client that use CMS, Commerce and Find translated to 15 different languages. Now they want to expand and add 25 new languages, so a total of 40 languages. Most of the new 25 languages will just fallback to the existing english site. I spontaneously got the feeling that 40 languages could be quite heavy (bad for performance), but it's nothing but a gut feeling. To summarize, 15 translated sites and an extra 25 languages that fallback to english. In the future, the fallbacked languages might be translated as well.
One thing that made me a bit reluctant was not knowing whether the new languages, although fallbacked, would create extra documents in Find - and therefore risk reaching the document limit of our license.
Do you have any good or bad experiences with sites with many translated sites? If good - maybe shed some light on if you made some special adjustment to cope with the amount of languages. If bad - what is/was your issues, did you solve them and how did you solve them?
Episerver find will only index the language branches that you create. You may add more langues to your site, without affecting numbers of documents indexed.
Given a site with 100 languages, even with fallback. If you create 10 language versions for one page, the Find index count should be 10 - not 100.
What about resources that editors have no access to (located in XML language files)?