Discoverability is the largest obstacle for affiliates and smaller partners. Allegedly this Boost will only get you higher on the recommended channels. The boosts may bump up the streams on the "Recommended for You" tab and on the front page landing. But I sort by Hi->Lo viewers so I will dodge that completely. And my bookmark is on Twitch.tv/directory so I already dodge the front page by default.
A lot of the old time streamers see this as a trap for the affiliates/new partners. Pay for the exposure, but then get trapped on the treadmill where paying for exposure is the only way to garner views. And Amazon gets bits and ad money without much work.
Re: discoverability - https://twitter.com/negaoryx/status/1443692439215108120