How about batching the upvote tx? In bitcoin-batching cuts fees majorly and even can help the LN reach massive scale. In steem-there is still batching but just combining request into one mega tx. It not that worth if you consider the cost. Steem has free tx :P
But wouldn't batching similar request help "scale" steemauto?
Say for trail and 20% of the people picked 30 minutes-combine that 30 minutes in one "tx". It way to simple on what I wrote but it a possible solution...