Thanks. I will most definitely check it out. However, how does it exactly work? You register, and you have your own account. So information is stored regarding your UTXOs that you've checked there. I don't see a privacy policy. What data is collected on an user? If there is a single point of storage (an Account) that means that a set of UTXOs could be grouped to the same person/entity. I find this a risk, at least within an anonymous service. I would need some more data on how you run it, but it was great that you disclosed BitOK as a source of your database. Most other do not even bother being open source about those things so you can't really know if you are being given some random report.
The "account" is just a token. We don't even ask for email.
The only data that's collected are the users' addresses they send to the checker. This is so that they can be forwarded to the API, and the results are cached so that a subsequent request shortly doesn't burn credit.
Also you'd need to purchase a small amount of credit for evaluation purposes. There is no free trial.
In that case, you would need to use one so called token for each UTXO lookup, otherwise there would be too much centralization risk as it would be obvious they all belong to the same user, and that you want to avoid at all costs. But this wouldn't allow to extract a report from the list.
Perhaps you could come up with a zero-knowledge-proof solution in which the user is safe from this centralization risk, otherwise you may need to do individual lookups and then collect all the data and do a report yourself.