Using SVG for diagrams means we can localize them, if we set things up the right way. I think that’s something worth investigating. There’s a blog post that uses a Django component to handle localization of content, and I’m sure there are similar tools for other environments as needed:
Do you have some example diagrams that you’re looking at?
Using SVG clearly makes diagrams easier to localize, but the example in that blog is nicely optimized for l12y.
Diagrams with visuals around a piece of text might pose a still-hard problem. So, if there’s a box around a piece of text, that won’t resize with changed text, for example.