Our apps do not support Opera later than Opera 12.  We were planning on continuing support a couple years ago, when Opera 15 first appeared.  But after two years, you’re the first one to mention it.  Good thing we ignored it, because Opera changed their bookmarking system, then the change was not well received and they made more changes.

Up to this point, our conclusion has been  that not enough people are using this moving target to bother with it.  I have not looked at it lately.