I don't think we need a special rewards pool for short-form content. HP holders can decide for themselves where to direct their Votes and thus influence value distribution for the existing pool.
My understanding is that 3-speak up votes content based on its popularity/views, so that might be more in line with your thinking.
When I look at snaps or threads, I always have the feeling that people are holding back their upvotes. It's mostly somewhere between 1 and 10%. I believe that a nice short form post that enhances a lot of interaction could be worth a 20% or 50% upvote as well :-). I agree that there is no need to add additional reward pools for it but I wouldn't mind if the voting power is slightly distributed differently :-). Thanks for stopping by!