On the surface this looks good but I'd be worried that it would also present somewhat of a barrier to growth of the Steemit front end, as a whole. It could easily be seen as "newbie unfriendly."
Maybe if it were coupled with something else (number of comments left in the past 24 hours? Current voting power?) it might become more workable.
Still, it sounds like a pretty good idea... but I'd need to sit down and truly "get inside the heads" of your typical spammers and scammers to fully understand what an effective tool would look like.
It all depends on how many authors will use this. If it gets widely adopted, yes, it may create some barriers. But look at the typical Medium post: a lot pf claps, but hardly any comment. Only really viral posts have dozens of comments.
We may have a lot of comments on Steemit right now, but the real contribution to a meaningful conversation of many of them is close to zero.
What worries me about the comment level at the moment is that so many are left by upvote bots. I look at some of the daily stats, and comments per post are declining... I just wonder HOW badly they are declining, once you remove bot comments. Can't be pretty.
I really wish there were a way to increase interest in human curation and interaction...