Curious why you sell right away? No faith in your company or is there another reason I'm missing?
If the answer is no, then it makes sense to sell immediately.
I thought there might be some kind of specific tax loophole or trick to moving the money out of the ESPP. I'm finding more and more of these tricks as time goes on, such as post-tax traditional 401k mega-backdoor Roth money (if it lasts past this year), etc...