one check
Client hints on three paths
The same facts travel three ways: JavaScript asks for them, the browser sends them as headers, and the TLS handshake underneath says which engine is really there. Whether all three agree is the part a general fingerprint viewer cannot check.
What this one page cannot tell you
Which hints a given site actually requests. Only a few are sent unasked; the rest arrive on a second request after the server asks. A blank on the header side here is ordinary and never counted against you.
The interesting part is usually not a single value but the disagreement between two. The full check reads all five layers and shows you where they contradict each other.