Oh that field is missing indeed. From what I know though, it can’t be filled with “tinybert” as it needs to be a model type implemented in the library, so I think it should be “bert”. As for adding it, I think it needs to be done on our side (in the future we’ll have the ability to open PRs on model repos, which would help in that case!)
Looking at that config, there are a few things that are a bit weird, so it may be that they have an internal class for those models not compatible with Transformers.