A poll in which "First choice is someone other than Trump" beats "Trump" would indicate that "Trump" has less than 50% of the vote. The same can be said of Harris.
A poll in which "Anybody but Trump" beats "Trump" would indicate that third party voters do indeed favor Harris over Trump.
Do we have any polling of the second type? I am not able to find any. This type of polling would be exactly what i've been asking for in this thread.
I mean.. thanks for the input, but you're just one person. I too would choose Harris over Trump if i was forced to choose between the two. But your and my personal choices to not a general consensus make. I wouldn't argue that the majority of 3rd party voters would do likewise without some proof.
.. none of this addresses that third party voters may find it more important to vote against BOTH parties than to vote against their least favorite of the two, either.. but i've raised that point elsewhere.