I was adamantly opposed to paying $10 for Roadblock without a trial period, but the dev emailed me screenshots showing how it would deal with one of my situations, so I took the plunge, and I'm pleased as punch to say that it does precisely what I was hoping it would do.
It ain't the least bit elegant, it's clunky, and its GUI could be better, but it 's the only replacement for AdBlock's "Block an element on this page" functionality that I've run across, and in that respect, it's MARVELOUS!
It's really difficult to evaluate an ad blocker's functionality, so I won't even try, but for the purpose for which I purchased it, it's 10 stars!