Heard a guy on a podcast talk about this exact thing with old boilers. He said the biggest jump usually comes from fixing the air flow, not just hitting it harder with more steam. Sounds like you figured out the same deal, getting that much ash out in 3 shifts is no joke. Idk if it was soot blower timing or pressure but whatever you did clearly worked.

Man, air still saves me hours on muddy bikes and I never had grit past seals.

Does heat really kill em though? My 4K boxes been fine crammed tight.