Ran into exactly this while maintaining a set of Claude Code skill files - bold markers creeping in every time something felt important enough to flag, then never removed once the next thing needed flagging too. The distinction worth adding to yours: a lot of our own files don't lean on inline bold at all, they lean on a dedicated header sitting alone before the rule rather than a marked phrase inside a paragraph. That's structurally closer to your "position first" point than to emphasis, since the model sees a section boundary, not a weighted span within prose. Worth asking whether that generalizes - does a whole-block callout carry the same instruction-following signal as position and repetition, or does it degrade the same way once there are twenty of them and none stand out anymore?