I still think you should try not to exceed 255 characters, at least for the part before the hash sign. A good URL should not change, and anything this large is almost bound to change rather soon.
The data URI scheme does not really apply here since it's never sent to any server. If a browser understands data URIs, it should logically also allow such long URLs.
The data URI scheme does not really apply here since it's never sent to any server. If a browser understands data URIs, it should logically also allow such long URLs.