Scoring Reftests

I was drafting up advice for when to split out reftests into multiple files or gather them into a single one, and one concern that came in was “combining reftests affects scores in WPT”, which... is not great. :/ Can we make this concern go away somehow?

I would like to be able to give advice based on arguments like “significantly improves understandability of the tests by factoring out common code on related test variants”, or “makes it easier to understand test results by keeping Level 1 and Level 2 features separate”, or “reduces test running time by an order of magnitude”, rather than bringing WPT test scores into it.

(Similarly, I don't want this concern to start weighing into the choice of whether to use testharness.js or reftests. Reftests are far more comprehensive for layout, so there are good reasons to use them.)

Start by reading the discussion about reftests, testharness.js, and how combining reftests affects WPT scores. Determine the scope and acceptance criteria for removing score-related concerns while preserving clear guidance on test organization and test type selection.