I would say it works as designed. That only unknown and multi need a corrected is a strange decision from groundspeek. Letterboxes is often not on the coordinates and wherigo is always not on the coordinates. Have had similar problem on earth caches
I have used corrected on trad where the CO have bad coordinates and dont update after logs about that
And you have the option "Require corrected" to only show caches with coordinates( in the gc special filed on in the notes) an not just a notes.
A types filer on that map might be useful