Understanding ranked choice voting in presidential primary

Bill Nemitz wrote a confusing piece in the Press Herald implying that ranked choice voting won't work right in a presidential primary because voters are selected for a caucus distribution - not a single candidate. In fact, Fair Vote - the movement behind RCV - clarified this a couple of month ago. including this:

Those casting RCV ballots will rank the candidates. If their first choice has at least 15 percent, their ballot will keep counting for that candidate. If their first choice is in last place and below 15 percent, their vote will count for their second choice. This will continue until all candidates are above 15 percent...

The 15 percent threshold set by the Democratic National Committee means that in primaries without ranked choice voting, any presidential candidate who receives less than 15 percent of the caucus or primary vote (either in a congressional district or statewide) will not earn any delegates, and their supporters’ votes will not help nominate delegates nor help determine who is the strongest candidate among the top candidates.

When ranked choice voting is used, more votes count. This is how the tally will be done: There will be one RCV tally statewide and one for each congressional district, as Democrats award delegates based on both of those results:

1. Voters rank candidates in order of their choice.
   
2. If any candidates earn less than 15 percent of the vote, the ranked choice vote tally starts. The candidate with the fewest votes is eliminated and those voters have their ballots count for their second choice (or next choice among active candidates).
   
3. This process continues until all active candidates have at least 15 percent of votes. Delegates are then allocated proportionally.

 The full report is here.