The Energon Pub

Certain Mini-Cassette Transformers (namely the reissues packed in with Twincast and Soundblaster, not 100% on anyone else) released during The Headmasters, as well as certain reissue-line redecoes like Stripes, Flip Sides, and Enemy, had stickers on them with a gimmick similar to the decodable Tech Specs, where viewing them through the red doors of Soundblaster and Twincast would reveal the weak spot of Fortress Maximus or Scorponok.

Thing is, looking at the photos of this in action in the galleries here... I'm not sure how to read the stickers, what the red filtering helps clarify. Is it just supposed to make it easier to see which of the circles has a blue border because the others are more obscured?

I've also noticed some inconsistency with regards to which circle has the border. On Flip Sides, her Fort Max sticker has the bordered circle be the bottom right, but on the Buzzsaw that comes with Collection Soundblaster, it's the circle on the top right, and on the Enemy and Wingthing that come with Encore Soundblaster it's the circle on the bottom left.

Was this inconsistency also present on the vintage The Headmasters cassettes with these stickers? If not, which placements did those cassettes use?
I have made efforts to research this myself via eBay, discovering a single listing for an original Soundblaster; the weak spot sticker on the Buzzsaw there puts the border on the top right circle (as with the Collection release), which would seem a tentative answer on the Decepticon side of things... but I don't know 100% if the repack Buzzsaw was the only Decepticon cassette with a weak spot sticker in the actual vintage Japanese line, or even if which circle had the border was the same between samples of him.
I also was not able to find a similar listing of Twincast (only the eHobby and Encore reissues), so the Autobot side of things is still a complete unknown.