I would not get another iFlight replacement. They did send me a replacement FC (and a free little quad) but the replacement FC is bad and even the FC in the free quad is bad. I will never purchase another iFlight electronics anything. Their Xing series motors seem to be OK.

EDIT:

The little Baby Nazgul iFlight sent me is fine. The reason I thought the yaw was not working is when I plug it into Betaflight, it shows pitch and roll working when I move the quad, but no yaw when I spin it. I tried plugging in a couple of older FC's and they show no yaw in betaflight as well.
I plugged a battery into the Baby Nazgul and yaw is working and it flies fine.

Now I am confused as to why Betaflight is not responding you yaw when it is actually working.

EDIT2:

It turned out the replacement FC worked fine as well. It came blank with no settings and just needed a full dump copied to it to set everything up properly...