What is the proper way to refer to the Original Poster (OP)?

In a Stack Exchange comment, I was corrected by referring to a user named alice as a "he". I said (context):

I know he thinks he needs all of the eigenvalues, but I've learned that ...

and was corrected to by another user

But a protip: the username "alice" and the pronoun "he" typically don't go together. Probably better to stick to gender-neutral singular they.

Which of these would be correct?

1. I know he thinks he needs all of the eigenvalues, ...
2. I know he/she thinks he/she needs all of the eigenvalues, ...
3. I know they think they need all of the eigenvalues, ...
4. I know the OP thinks they need all of the eigenvalues, ...

Clearly this question is related:

Is there a correct gender-neutral singular pronoun ("his" vs. "her" vs. "their")?

I'm interested in the last case where OP is essentially a pronoun, but the usage sounds awkward. Is there a good way to refer to OP or should I stick with "they"?

Solution 1:

As the comments say OP is a noun here.

He/she is too longwinded. "They" is gender neutral. Theirs, they're, they are, them etc.

I would go with option 4 as it identifies "them" as "the OP". Option 3 could confuse readers about who the actual subject is.

Solution 2:

For what seems to be the core of your specific question - I think #4 sounds better than #3; it's not 'more correct' gramatically, just a matter of style.

I'll repeat here what has been beaten to death elsewhere (including the question you linked): "He" is gender neutral. "She" is not; I'd think it a greater mistake to use "she", thus declaring an assumption about the gender of "alice" (esp. on the internet). Because "he" is gender-neutral, it doesn't actually suggest such an assumption.

"He/she" is a little off, as others have said "he or she" is a little clunky (although correct).

There are others (like the answer you linked), who know more than I, who will insist that singular "they" is OK. I'm sure those folks have a good argument, but to my old-fashioned, prescriptivist ears, it's not.

I thought of the same example as @Mari-LouA - "the captain". "The captain thinks he needs full engine power." / "The captain thinks they needs full engine power." Doesn't the former sound better?