As you’ve already seen, there is a uservoice item for that request and that is the appropriate place to leave feedback on requests for new features.
Just because Twitch haven’t responded doesn’t mean they haven’t seen it, they do check UserVoice as that’s where they direct people to post feature requests and see popularity/use cases to support the requests. It’s likely that this feature simply is a very low priority, it’s a nice feature sure but not critical to 3rd party developers compared to other functionality that still needs to be ported from v5 to Helix.