Personally I’d rather see Twitch spend engineering time on features that would actually benefit the larger user base. These changes would only benefit a very small group. If a developer wants to create an application using TMI then the functionality is already provided or could be provided in better ways (ex: REST API for a channel’s chat status [slow mode values, mods, etc.])
There are 7 (maybe 6) modes you would need to support for users. Otherwise you’d have to use both these and v3 tags to provide this information. (Staff, Admin, Global Mod, Broadcaster, Channel Mod, Subscriber and Turbo)