I tested overriding the explain endpoint and it works fine. The downside is that we use a post method.
Another option would be to manipulate the FastAPI object and add a route to it, but it doesnt seem like the best option as we would have to make sure this doesn't break in future versions.

Regarding revertrisk models, supported wikis can be accessed both for multilingual and language-agnostic models by accessing the supported_wikis attribute of the model class which is a list. (model.supported_wikis). This means that if we decide on a schema for metadata for our models we can implement the explain endpoint for revertrisk.

I have opened the following issue on GH https://github.com/kserve/kserve/issues/3098 and also opened a relevant conversation in the community's kserve slack channel.

On top of that I tried (but have not yet succeeded) to override the model_ready function which defines the endpoint v1/models/model_name as mentioned in the routes file.
I just defined a new function named model_ready which outputs a bunch of model information other than the standard response which is {"name": model_name, "ready": model_ready}. In my experiment the standard response is returned instead of my enriched one.