I wonder how much putting a CDN in front of this would reduce this.
According to the readme, it seems like the bulk
of the traffic is highly cacheable, so presumably you could park something a CDN in front and substantially reduce the bandwidth requirements.
Yes, the static-ct api is designed to be highly cacheable by a CDN.
That is one of the primary motivations of its design over the previous CT API, which had some relatively flexible requests that led to less good caching.
According to the readme, it seems like the bulk of the traffic is highly cacheable, so presumably you could park something a CDN in front and substantially reduce the bandwidth requirements.