According to it's wiki, it should be tagged. (not a doll, not a painting, character is actually there)
Digging through old posts, i didn't find a specific answer.
However It seems opinion/intuition differs & thus doesn't get tagged consistently.
Sidenote, solo still applies to random faceless and is tagged much more often, thus is good for refining this sort of search.
chartags:1 sex - A large amount is 1girl + random faceless or floating part.
Sample of ~1200 posts
"1girl without 1boy" is tagged 731x
"1girl 1boy" is tagged 386x (note, includes some results where the guy is completely visible)
And 68 aren't tagged *girl(s)
Could be interesting:
chartags:1 sex solo +/- 1boy
hetero 1boy solo
faceless rating:e
As well as 1girl 1boy solo?
Personally, the face being cut-off vs faceless makes quite a difference. As well as the rating.
If someone searches for 1boy, would they want to find images with floating parts/hands/arms? Probably not
If someone blacklists it, would they want to hide those images? Maybe
Updated