Can this support more domains to track?

[lolifamily]

You can try to use self request(making request to itself and add a parameter of the subrequest) and each subrequest can track 25 domains so that it's able to track 50*25 domains.

[eidam]

This is not possible with KV at this moment as you might end up with rewriting the state pretty often. But I will check once there will be an open beta for Durable Objects.

[itsmatteomanf]

You can try to use self request(making request to itself and add a parameter of the subrequest) and each subrequest can track 25 domains so that it's able to track 50*25 domains.

You also can't technically call the Worker itself unless you do a staggered "domain > workers.dev > domain" and so on...