Watched a finisher do the thumb test on a slab once and it changed how I check wetness forever. Press your thumb into the cream near where you're about to broom. If the print fills back in with water, it's still too wet and you'll drag up a glossy smear. If the print mostly holds its shape with just a little bleed, that's your window. Also watch the sheen, not the clock. The moment the shine goes dull and matte across the whole slab, you got maybe a couple minutes before it's too stiff to pull a clean groove. Humidity in Tulsa will wreck any time based rule you try to use, so trust your thumb and your eyes over how many minutes have passed.

Patched two holes myself last year after a guy "misread" his work order, so I feel your pain. My best fix so far has been taping a giant note to the door, since apparently house numbers are just decoration.