I have one piece of perhaps useful input here, from one of the schools being discussed: Brown.
Our specific HS does not rank…but our school system requires the inclusion of a rank (using weighted GPA on a 5.0 scale) on the transcript. So officially we don’t rank, but schools will see the rank anyway. 
Our school counselor reached out to Brown to understand how they will approach this situation—school does not rank, but a rank is evident on the transcript.
They sent a lengthy response. Here are the two key excerpts:
“We would like to emphasize first that while Brown tends to attract applicants who have performed exceptionally well academically, there are no minimums or cutoffs in our application review process.”
[Lengthy interlude where they describe what they look for in their holistic review. It’s all the usual stuff!]
“When we begin to review an application we consider all of the information available to us at the time. If information, such as class rank, is included on a transcript than we will consider it within a holistic review as one of many factors.”
I take this to mean that they look at raw rank as provided by the school (or school system, in our case)…but that they also don’t apply arbitrary cut-offs, which supports the idea that the raw rank alone isn’t particularly helpful to them.
Given that 93% of Brown’s enrolled students last year were in the top 10% of their classes, we can assume that there is something of a cut-off at 10%. But then, that data point presumably reflects only those who provided a rank (which we know many schools do not) and includes all of the students from schools who give a #1 rank to everyone with a 4.0, etc. So it’s still not clear that it’s not super-meaningful.
Anyway…just thought I’d share this given that Brown bothered to answer the question!