As more people in todays society begin to experience loneliness and isolation a new phenomenon has occurred, this is React content. Many people today prefer to watch content alongside their favourite content creators, either to validate their views, gage their responses or just to feel less alone. 

However the concept of reactions are iffy on YouTube at best. With creators infighting and striking their peers for reuploads, large corporations exploiting a vague and ever changing copywrite system and many more issues.

As Such this is how I would solve the issue posing as the giant conglomerate YouTube itself.

From this point on I will refer to the UPLOADER as the creator of the original content and the REACTOR as the creator that reacts to said content. I would start by creating a simple system that takes the length of the reaction clip on the Reactors video and for every second viewed on their video it is duplicated back onto the original Uploaders video (with the matching view time spikes relative to the clips they use).

This allows the Uploader to feel compensated outside of "Exposure" and can provide them with some extra insights whilst not demonising the Reactor.

As an uploader it is important that you are given the choice to whether you want people to react to your content or not. And this shouldn't be held to vague guidelines and perceived social norms and curtesy. As creators they should be able to decisively show that they are or are not happy for users to react to their content and not leave it to interpretation.

As such I propose a simple 3 stage Reaction option of which you can set a default for all uploads and adjust individually per video. These are comprised of :

Allow all reactions - This allows other creators to upload their transformative reactions to your videos.

Allow Users to request reactions - This allows creators to create a whitelist and blacklist of creators that can react to their content on both a channel wide and video specific level.

Do not allow reactions - As it sound stops reactions and allows the user to take action easily on channels using their content.

In the YouTube editor I would add a reactions segment that allows the user to designate reaction segments similarly to how they add timestamps. To do this I would leverage YouTube's content ID system to identify other users content and automatically timestamp them as well as alert to any content that can't be reacted to. The Reactor can then add any unnoticed clips or adjust any incorrect Content ID sections. 

By doing this, this would also be rewarded by helping fuel SEO and feed into the algorithm by drawing direct links between the reaction and original content.