I'm curious, you compared this extra filtering at any kind of scale?
Yes, I have 100's of KGR "style" posts spread over 3 sites in different niches, and have just started a fourth. When analyzing the rank and extra long tail traffic of articles that are doing well, I found the majority fitted this new formula. Of course I still check competition strength and quality of content, but 0 - 5 allintitle, broad match and under half a million competing sites, almost always hit the top 3 spots with decent content, without links.
I know your in to automating the process, and want to scale, I too have tried going down that route, but as stated above, manually digging through Google with nothing but KWE activated, is the only way to find these very easy to rank terms.
My new project is almost the complete opposite to what your doing, with content fit to rank for even the most difficult keyword, posts that take weeks, with own photos, videos, tables and graphs, very precise keyword research, low comp starter niche, and by low comp I mean very few active SEO's, plus I'm building the site and content to be very EAT compliant.