If you just seeded it you're probably not going to see significant spreading until next year. It will not crowd out other grasses, it's not that aggressive. With that in mind, it's now up to you to decide what you can tolerate as far as bare spots. You could always rough up the soil and drop more seed. Or pull plugs from other areas.

Thanks lawniac. I'm not surprised, so off to work I go. I do have an irrigation system and that will allow me to refurbish small areas with constant moisture control for new grass seeds if they are needed. Hopefully, by fall I'll be able to post some photos showing a reasonably nice KBG lawn. We'll see. Thanks again for your reply.

KBG will not outcompete other grasses IMHO. If you kill undesirable grasses here or there, it will fill in but it won't displace other living grasses that are there. How fast depends on the quality of your soil. It does spread into flower beds quite easily. I use the flower bed growths to transplant into the lawn every year in places where I dug out or rounded up weed grasses. Just makes for a better look and speeds the process of filling in faster.

Thank you mishmosh. I have started doing the same thing and appreciate your comments. I have not transplanted any KBG yet, but plan on doing that as well as time goes by. I use a zero turn mower and with my best attempts, I occasionally get a divot in the lawn. Frustrating, but seems to be a fact of life with a zero turn mower. Life would be easier if lawns were always at the appropriate dryness for mowing. I know, one wheel moving backward and the other moving forward. Sounds easy but I still get the occasional oooops. Suggestions for this issue would also be appreciated by some of the expert mower operators. :-)