It looks like Sunny Lubana bagged the biggest stack from Day 1a with 35 players advancing to Day 2 from the opening flight. He had 1.1 million in his bag at the end of the night, the only player in seven digits.
Shane Brotherwood, Colten Yamagishi, and Michael “Berny” Bernstein bagged in the 600k range with Pavlo Vertiiko rounding out the top five with 593k. Full qualifying stacks for Day 1a are below with the caveat that there was no chip count on one bag so Talal Shoush is listed as DNR, but he for sure has a bag in play for Day 2.