Playing the devil's advocate. Let's say I believe Democrats who say the total number is not reflective of the final mail in ballot votes.
Even if that is true, it means that the final mail-in ballot total was... exactly 40k. Not 41251, not 38577, or some random number, but exactly 40k.
And in that 40k, 99% went to Biden.
That's what they want you to believe. Hilarious.