No boards read yet, and here is how one happens.

Capture a profile or a hashtag in the extension until the board has a dozen posts or so, then hit ⌗ Name the formats. It reads the top of that board as your sort and filters have it — not every post you captured — and groups what it read into the shapes that actually repeat, counting each shape against those posts. The read is saved here.

It never spends a generation, and every number it reports is counted from your own posts rather than written by the model.