KBG takes longer to germinate so if you're sure there's seed there I'd let it be and see if it comes in. Grass should start growing quicker now that temps are coming down a bit.

You don't want to overcrowd the area with more seed...

Thanks. For reference, here are a few pics I snapped of some of the
thinned out areas. Still unsure whether to try to let it fill in on its
own or throw down some quick grow seed this weekend.

Jon-

It's hard to see clearly because the pics are small. Maybe a wide shot of the whole lawn and then one really close up of a bare spot?

However, particularly picture #2, that looks very patchy to me for 4 weeks time.....did you use a spreader?

Yes, I wasn't 100% on the spreader setting as the bag just said 6 lb/1000 sq ft for a new lawn. I have a Scott's broadcast spreader and put the setting at 6 because I read a few places that equaled pounds per 1000 sq ft.

I just took a look again this morning and it seems like the KBG is finally starting to pop up in the bare areas. I’m going to feed the grass with Milo tomorrow (first post-germination feeding) and hope that helps thicken it up