Just be patient. What you did was the equivalent of mowing with a horribly unsharpened blade. That's not fatal, it's just horribly, horribly ugly. Let it grow out and the next cut will take the damage away. Given the overseeding, that's going to be a bit (you want to give the seed some time to sprout before walking your lawn), but it's going to be just fine.

There's no need to delay the Tenacity, but you can if you want. A one-day delay will give the wounds time to clot and dry and seal closed, although the Tenacity is going to absorb through the grass blades anyway.

Thanks for the comforting words. I can’t believe I did that. Gave the lawn a good dose of milo so hopefully it’s comes out thick