We had something like that for comment votes back in the day, but automated voting on comments is pretty problematic. Might work okay in specific waves containers, but there are a lot more limitations around quality.
I have some ideas around signaling votes (Hive SBI users upvote a comment, that signals to our program that the comment is okay to upvote, and it also receives votes from us) that integrate into our tentative DAO design, but our dev budget is very limited right now.
For sure automatically upvoting comments can be a problem :D
Waves might be a little different in that regard ^^
Looking forward to it whatever feature you come up with ^^