You're right that a few large operations managed to install monitoring system (at least they got that right finally). The calculator, even at this beta stage, can be useful in specific cases like calculating downtime/opportunity loss/missed. And I already talked to some users who used it to get precise, verifiable numbers in such a case.
Also not just mining farms—it’s a profitability estimator for cases like opportunity loss from curtailed wind energy for example: in 2023, Northern Ireland had to curtail 539 GWh of wind energy. To put that into perspective you can translate it using the calculator into 60MW of unutilised capacity or 534 BTC mined on s9... on that point have an idea to have a real-time conversion of curtailment data (if i find a grid which is streaming such data)
I also know the experience of small miners who have several megawatts of capacity. So they don't have all asics mining 24/7. Some asics are on testing, some are under warranty and non-warranty repair, some work with low mining parameters due to manufacturer's defect, but the warranty is over.
And the situation is changing every day, new data centres with 50-100 megawatts are being opened.
That's why I don't understand how you will make a perfect calculator if it is impossible to do it.
The most powerful computing centres in the world are trying to predict the weather, they have a huge database, but you can look at the weather forecast for 2-3 days ahead and then compare the results.