Multiple reports are NOT merged - each report stands on its own, no time series is created.
Nexilon Tools
Nothing leaves this window. Processing happens entirely in the browser - no transmission, no upload, no external resources. Enforced by Content Security Policy. Source IP addresses are shown exactly as they appear in the report - not resolved (no rDNS, no WHOIS, no ASN lookup), because each of those would require a network request.
How to check it. Open this tool via "Open in a new tab" and then the network panel of your browser: apart from the document itself, nothing is listed there - not even while you load a file into it. Inside the frame of a web page you additionally see the entries of that page; the tool requests none of them.
An empty network tab only shows that nothing was loaded, not that nothing can be loaded. The rule is in the source code of this file as Content-Security-Policy and can be read there.
Multiple reports are NOT merged - each report stands on its own, no time series is created.