This is also important as users should be allowed to use all markings by default for presets, but because mass markings includes markings without explicit permission from their owners, they aren't able to be used. Hopefully this will change in the near future!
asdfghj I don't want to sound rude but I think some of the default markings were made by Nala91 and she doesn't want people to use the them for presets. She made a thread about this a long time ago but I currently can't find it, however she does have a Deviantart journal regarding it. https://www.deviantart.com/feral-hearts/journal/Markings-being-used-for-presets-Big-no-no-328155419
As for the rest of the markings I'm not so sure though.
No, you’re all good! I was mainly refering to only mass markings because even if the artists don’t mind users using their markings in presets, it was never explicitly stated, making it a shot in the dark, considering some of the artists are unknown and/or retired from FH.