I was able to score a set of replacement tires and tubes - you just need to make sure you sign up for in-stock alerts and then buy them as soon as you get the alert.

here's some info from their installation guide that I thank may help - but I think you may be right, too small a hole for that nut:

"Check if the headlight bracket is compatible with the front rack.

For 2020 and newer models, RadRunner, and RadMission models: The headlight bracket installed on your bike is compatible with the front rack. The additional bracket included with the front rack accessory is not necessary for installation.

For 2019 and earlier models: The headlight bracket is not compatible with the front rack. Follow the steps below to install the headlight on the compatible bracket."

More info here: https://radpowerbikes.zendesk.com/hc/en-us/articles/360043000914-Front-Rack-Installation-Guide