No PSF candidates survive

Hi @raphaelshirley, I am just following up on unsolved topics in Support. It looks like, in this case, some of the suggestions unearthed some underlying issues that have been pursued in other topics: " The obs_decam nullIsr task" and " Negative peaks in calexp files". I was wondering if (for posterity) there are any final comments or takeaways for anyone else who might have similar issues in finding and using PSF stars in low SNR images?