Not that I’ve heard about.
This is probably a good idea.
If you are doing enough stuff client side to worry about needing to run close to the rate limit, you probably want to be using an “App Access Token”, (if you don’t have a user access token, via implicit auth), and to generate those means using your server with the client ID/secret to generate it. And you don’t want to leak those to the front end really.
So I don’t think Twitch will consider adding it. But you could add it to the Twitch Dev uservoice
https://twitch.uservoice.com/forums/310213-developers
(Basically, unless getting public data, I get my server to do it anyway via Relay, and when I’m doing public I know it’s about 3/4 API requests and no where near the unauthed 30)