I'm suddenly very interested in the distinction here - as yea themself also works in both of these contexts but themselves feels like a very distinct connotation and not incorrect. I can't point to a specific grammatical rule or learning to base this feeling off though - I don't know why it feels correct it just does.
> A reflexive pronoun is a pronoun that refers back to the subject of a sentence or clause. You can recognize a reflexive pronoun by its second half: they all end in -self or -selves. [...] Only the dual-purpose your* has two reflexive forms: singular yourself and plural yourselves. [...] But if you'd been typing in the late 1300s, themself would have been the default: it was the only version around until the mid-1400s. [...] Eventually, themselves became the only accepted form. But themself never fully disappeared.
