As you already know, I have been experimenting with a bit of automated curation myself with an alt account. Specifically, I am working on preventing certain comment votes from coming in under the dust threshold.
In my view, curation is currently best done with specific users in mind rather than content: users we don't want to lose; users who, while their stake may be low, will bring value to the platform through their continued engagement.
Right now the incentive is simply not there to engage for these people, unless they are blissfully ignorant of the dust threshold. Comments usually only receive one vote (from the person on whose post they are made). Once these engaging low-SP users find out that their 100% vote (or that of a majority of their followers) is completely wasted on a comment, I can see them coming to the conclusion: "why even bother?"
I understand that there are those who feel that automated curation is the devil, and I suspect I won't win popularity with those people by doing this, but I do hope that my intentions are well-received.
This is what I think too. And if it happens at all levels it creates a healthier system all up. It is difficult to find balances and, everyone thinks that they bring value and quality to the table (I get DMs a couple times a day) and that they are under-rewarded. It is impossible for everyone to consistently get support but if the place can't keep the people it wants to keep, there are going to be bigger issues to come.
There is just no way to do what you have been doing manually either.